Update Debugger Labels (dotnet#4798)

This PR updates the debugger labels to be:

.NET Core -> .NET 5+ and .NET Core
.NET -> .NET Framework 4.x (Windows only)

Author: WardenGnaw

package.json

@@ -1062,7 +1062,7 @@
     "debuggers": [
       {
         "type": "coreclr",
-        "label": ".NET Core",
+        "label": ".NET 5+ and .NET Core",
         "languages": [
           "csharp",
           "razor",
@@ -2168,7 +2168,7 @@
       },
       {
         "type": "clr",
-        "label": ".NET",
+        "label": ".NET Framework 4.x (Windows only)",
         "languages": [
           "csharp",
           "razor",