Rewrite unified settings test (#76591)

Previously the test in
[src/VisualStudio/Core/Test/UnifiedSettings/VisualBasicUnifiedSettingsTests.vb](https://github.com/dotnet/roslyn/compare/main...Cosifne:dev/shech/upgradeUnifiedSettingsTest?expand=1#diff-d00c0d46bc861b74969a4a069ba220df3951e605514dd897bf9b89ddfe98f439)
does not cover all the properties (especially, the localization string)
in unified settings registration, and we have regressed the strings back
in
dfc660c#diff-a16de2a58a10f14a7fc8512f47bbd467869339a6135046bb0274d2fce1151f93R1901

This PR revises all the tests using STJ instead of using JSON path to do
all the assertion.
Also it modifies a few strings to fit the unified setting model.

It's mainly a test only change.
The only difference in the product is in Unified Settting page:

![image](https://github.com/user-attachments/assets/1960bfb1-dbb2-4ec5-92f9-ac0b1e2d0091)

Author: Cosifne

src/EditorFeatures/CSharp/Microsoft.CodeAnalysis.CSharp.EditorFeatures.csproj

@@ -34,6 +34,7 @@
     <InternalsVisibleTo Include="Microsoft.VisualStudio.LanguageServices.LiveShare" />
     <InternalsVisibleTo Include="Microsoft.VisualStudio.LanguageServices.CSharp.UnitTests" />
     <InternalsVisibleTo Include="Roslyn.Hosting.Diagnostics" />
+    <InternalsVisibleTo Include="Roslyn.VisualStudio.Next.UnitTests" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Update="CSharpEditorResources.resx" GenerateSource="true" />

src/VisualStudio/CSharp/Impl/CSharpVSResources.resx

@@ -449,9 +449,12 @@
     <value>In other binary operators:  &amp;&amp;   ||   ??   and   or</value>
     <comment>'and' and 'or' are C# keywords and should not be localized</comment>
   </data>
-  <data name="Show_name_suggestions" xml:space="preserve">
+  <data name="Show_name_s_uggestions" xml:space="preserve">
     <value>Show name s_uggestions</value>
   </data>
+  <data name="Show_name_suggestions" xml:space="preserve">
+    <value>Show name suggestions</value>
+  </data>
   <data name="In_relational_binary_operators" xml:space="preserve">
     <value>In relational operators:  &lt;   &gt;   &lt;=   &gt;=   is   as   ==   !=</value>
     <comment>'is' and 'as' are C# keywords and should not be localized</comment>
@@ -533,6 +536,9 @@
   <data name="Show_new_snippet_experience_experimental" xml:space="preserve">
     <value>Show new snippet experience (experimental)</value>
   </data>
+  <data name="Show_new_snippet_experience" xml:space="preserve">
+    <value>Show new snippet experience</value>
+  </data>
   <data name="Allow_blank_line_after_token_in_conditional_expression" xml:space="preserve">
     <value>Allow blank line after token in conditional expression</value>
   </data>

src/VisualStudio/CSharp/Impl/Microsoft.VisualStudio.LanguageServices.CSharp.csproj

@@ -51,10 +51,11 @@
     <InternalsVisibleTo Include="Microsoft.VisualStudio.LanguageServices.UnitTests" />
     <InternalsVisibleTo Include="Microsoft.VisualStudio.LanguageServices.Test.Utilities2" />
     <InternalsVisibleTo Include="Microsoft.VisualStudio.LanguageServices.New.IntegrationTests" />
+    <InternalsVisibleTo Include="Roslyn.VisualStudio.Next.UnitTests" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Update="CSharpVSResources.resx" GenerateSource="true" />
-    <EmbeddedResource Update="VSPackage.resx">
+    <EmbeddedResource Update="VSPackage.resx" GenerateSource="true" Namespace="Microsoft.VisualStudio.LanguageServices.CSharp" >
       <MergeWithCTO>true</MergeWithCTO>
       <ManifestResourceName>VSPackage</ManifestResourceName>
       <SubType>Designer</SubType>

src/VisualStudio/CSharp/Impl/Options/IntelliSenseOptionPageControl.xaml

@@ -68,15 +68,15 @@
 
                     <CheckBox x:Uid="Show_name_suggestions"
                                   x:Name="Show_name_suggestions"
-                                  Content="{x:Static local:IntelliSenseOptionPageStrings.Option_Show_name_suggestions}" />
+                                  Content="{x:Static local:IntelliSenseOptionPageStrings.Option_Show_name_s_uggestions}" />
 
                     <CheckBox x:Uid="Show_items_from_unimported_namespaces"
                                   x:Name="Show_items_from_unimported_namespaces"
                                   Content="{x:Static local:IntelliSenseOptionPageStrings.Option_Show_items_from_unimported_namespaces}" />
 
                     <CheckBox x:Uid="Tab_twice_to_insert_arguments"
                                   x:Name="Tab_twice_to_insert_arguments"
-                                  Content="{x:Static local:IntelliSenseOptionPageStrings.Option_Tab_twice_to_insert_arguments}" />
+                                  Content="{x:Static local:IntelliSenseOptionPageStrings.Option_Tab_twice_to_insert_arguments_experimental}" />
 
                     <CheckBox x:Uid="Show_new_snippet_experience"
                                   x:Name="Show_new_snippet_experience"

src/VisualStudio/CSharp/Impl/Options/IntelliSenseOptionPageStrings.cs

@@ -9,10 +9,10 @@ namespace Microsoft.VisualStudio.LanguageServices.CSharp.Options
     internal static class IntelliSenseOptionPageStrings
     {
         public static string Option_Show_completion_list_after_a_character_is_typed
-            => ServicesVSResources.Show_completion_list_after_a_character_is_typed;
+            => ServicesVSResources._Show_completion_list_after_a_character_is_typed;
 
         public static string Option_Show_completion_list_after_a_character_is_deleted
-            => ServicesVSResources.Show_completion_list_after_a_character_is_deleted;
+            => ServicesVSResources.Show_completion_list_after_a_character_is__deleted;
 
         public static string Option_Completion
         {
@@ -35,10 +35,10 @@ public static string Option_ShowSnippets
         }
 
         public static string Option_Highlight_matching_portions_of_completion_list_items
-            => ServicesVSResources.Highlight_matching_portions_of_completion_list_items;
+            => ServicesVSResources._Highlight_matching_portions_of_completion_list_items;
 
         public static string Option_Show_completion_item_filters
-            => ServicesVSResources.Show_completion_item_filters;
+            => ServicesVSResources.Show_completion_item__filters;
 
         public static string Option_Automatically_complete_statement_on_semicolon => CSharpVSResources.Automatically_complete_statement_on_semicolon;
 
@@ -66,14 +66,14 @@ public static string Option_Always_include_snippets
         public static string Option_Include_snippets_when_question_Tab_is_typed_after_an_identifier
             => CSharpVSResources.Include_snippets_when_Tab_is_typed_after_an_identifier;
 
-        public static string Option_Show_name_suggestions
-            => CSharpVSResources.Show_name_suggestions;
+        public static string Option_Show_name_s_uggestions
+            => CSharpVSResources.Show_name_s_uggestions;
 
         public static string Option_Show_items_from_unimported_namespaces
             => ServicesVSResources.Show_items_from_unimported_namespaces;
 
-        public static string Option_Tab_twice_to_insert_arguments
-            => ServicesVSResources.Tab_twice_to_insert_arguments;
+        public static string Option_Tab_twice_to_insert_arguments_experimental
+            => ServicesVSResources.Tab_twice_to_insert_arguments_experimental;
 
         public static string Automatically_show_completion_list_in_argument_lists
             => CSharpVSResources.Automatically_show_completion_list_in_argument_lists;

src/VisualStudio/CSharp/Impl/PackageRegistration.pkgdef

@@ -198,4 +198,4 @@
 [$RootKey$\SettingsManifests\{13c3bbb4-f18f-4111-9f54-a0fb010d9194}]
 @="Microsoft.VisualStudio.LanguageServices.CSharp.LanguageService.CSharpPackage"
 "ManifestPath"="$PackageFolder$\UnifiedSettings\csharpSettings.registration.json"
-"CacheTag"=qword:3AEFDB0DA1308654
+"CacheTag"=qword:18C11F0A543B8AD0

src/VisualStudio/CSharp/Impl/UnifiedSettings/csharpSettings.registration.json

@@ -100,7 +100,7 @@
       "title": "@Snippets_behavior;..\\Microsoft.VisualStudio.LanguageServices.dll",
       "type": "string",
       "enum": [ "neverInclude", "alwaysInclude", "includeAfterTypingIdentifierQuestionTab" ],
-      "enumItemLabels": [ "@Never_include_snippets;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}", "@Always_include_snippets;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}", "@Include_snippets_when_Tab_is_typed_after_an_identifier;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}" ],
+      "enumItemLabels": [ "@Never_include_snippets;..\\Microsoft.VisualStudio.LanguageServices.dll", "@Always_include_snippets;..\\Microsoft.VisualStudio.LanguageServices.CSharp.dll", "@Include_snippets_when_Tab_is_typed_after_an_identifier;..\\Microsoft.VisualStudio.LanguageServices.CSharp.dll" ],
       "default": "alwaysInclude",
       "order": 50,
       "migration": {
@@ -136,7 +136,7 @@
     },
     // CompletionOptionsStorage.EnterKeyBehavior
     "textEditor.csharp.intellisense.returnKeyCompletionBehavior": {
-      "title": "@Enter_key_behavior_colon;..\\Microsoft.VisualStudio.LanguageServices.dll",
+      "title": "@Enter_key_behavior;..\\Microsoft.VisualStudio.LanguageServices.dll",
       "type": "string",
       "enum": [ "never", "afterFullyTypedWord", "always" ],
       "enumItemLabels": [ "@Never_add_new_line_on_enter;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}", "@Only_add_new_line_on_enter_after_end_of_fully_typed_word;..\\Microsoft.VisualStudio.LanguageServices.dll", "@Always_add_new_line_on_enter;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}" ],
@@ -209,6 +209,11 @@
       "type": "boolean",
       "default": false,
       "order": 90,
+      "messages": [
+        {
+          "text": "@Experimental_feature;..\\Microsoft.VisualStudio.LanguageServices.dll"
+        }
+      ],
       "migration": {
         "pass": {
           "input": {
@@ -220,9 +225,14 @@
     },
     // CompletionOptionsStorage.ShowNewSnippetExperienceUserOption
     "textEditor.csharp.intellisense.showNewSnippetExperience": {
-      "title": "@Show_new_snippet_experience_experimental;..\\Microsoft.VisualStudio.LanguageServices.CSharp.dll",
+      "title": "@Show_new_snippet_experience;..\\Microsoft.VisualStudio.LanguageServices.CSharp.dll",
       "type": "boolean",
       "default": false,
+      "messages": [
+        {
+          "text": "@Experimental_feature;..\\Microsoft.VisualStudio.LanguageServices.dll"
+        }
+      ],
       "alternateDefault": {
         // CompletionOptionsStorage.ShowNewSnippetExperienceFeatureFlag
         "flagName": "Roslyn.SnippetCompletion",
@@ -241,7 +251,7 @@
   },
   "categories": {
     "textEditor.csharp":{
-      "title": "C#"
+      "title": "@101;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}"
     },
     "textEditor.csharp.intellisense": {
       "title": "@103;{13c3bbb4-f18f-4111-9f54-a0fb010d9194}",