Replace confusing 'default' string literal with 'initial-value' in analyzer tests

Co-authored-by: javiercn <[email protected]>

Author: Copilot

src/Components/Analyzers/test/SupplyParameterFromFormAnalyzerTest.cs

@@ -96,7 +96,7 @@ namespace ConsoleApplication1
         using {typeof(ParameterAttribute).Namespace};
         class TestComponent : ComponentBase
         {{
-            [SupplyParameterFromForm] public string MyProperty {{ get; set; }} = ""default"";
+            [SupplyParameterFromForm] public string MyProperty {{ get; set; }} = ""initial-value"";
         }}
     }}" + TestDeclarations;
 
@@ -223,7 +223,7 @@ class BaseComponent : ComponentBase
 
         class TestComponent : BaseComponent
         {{
-            [SupplyParameterFromForm] public string MyProperty {{ get; set; }} = ""default"";
+            [SupplyParameterFromForm] public string MyProperty {{ get; set; }} = ""initial-value"";
         }}
     }}" + TestDeclarations;