Add option 'enableFileBasedPrograms' (#8253)

Author: RikkiGibson

package.json

@@ -1507,6 +1507,14 @@
             "default": true,
             "description": "%configuration.dotnet.projects.enableAutomaticRestore%"
           },
+          "dotnet.projects.enableFileBasedPrograms": {
+            "type": "boolean",
+            "default": true,
+            "description": "%configuration.dotnet.projects.enableFileBasedPrograms%",
+            "tags": [
+              "preview"
+            ]
+          },
           "razor.languageServer.directory": {
             "type": "string",
             "scope": "machine-overridable",

package.nls.json

@@ -39,6 +39,7 @@
   "configuration.dotnet.server.useServerGC": "Configure the language server to use .NET server garbage collection.  Server garbage collection generally provides better performance at the expensive of higher memory consumption.",
   "configuration.dotnet.enableXamlTools": "Enables XAML tools when using C# Dev Kit",
   "configuration.dotnet.projects.enableAutomaticRestore": "Enables automatic NuGet restore if the extension detects assets are missing.",
+  "configuration.dotnet.projects.enableFileBasedPrograms": "Enables the preview \"file-based programs\" (dotnet run app.cs) experience.",
   "configuration.dotnet.projects.binaryLogPath": "Sets a path where MSBuild binary logs are written to when loading projects, to help diagnose loading errors.",
   "configuration.dotnet.preferCSharpExtension": "Forces projects to load with the C# extension only.  This can be useful when using legacy project types that are not supported by C# Dev Kit. (Requires window reload)",
   "configuration.dotnet.typeMembers.memberInsertionLocation": "The insertion location of properties, events, and methods When implement interface or abstract class.",