Improve ordering in target framework dropdown

Previously the ordering was "natural" ascending. This created a block with ".NET 5+" items at the top, and ".NET Core" items below, however the newest .NET item (e.g. ".NET 9") would be in the middle of the list.

The change here adds sorting by group, then by version, and makes that version ordering descending. This means that the latest and greatest version is always at the top of the list.

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/Frameworks/SupportedTargetFrameworksEnumProvider.cs

@@ -85,6 +85,29 @@ protected override IEnumValue ToEnumValue(KeyValuePair<string, IImmutableDiction
 
     protected override int SortValues(IEnumValue a, IEnumValue b)
     {
-        return NaturalStringComparer.Instance.Compare(a.DisplayName, b.DisplayName);
+        // Order by family first, then by version (descending).
+        int comparison = GetFamilyRank(a.DisplayName) - GetFamilyRank(b.DisplayName);
+
+        if (comparison is not 0)
+        {
+            // Ranks differ.
+            return comparison;
+        }
+
+        // Same rank. Large numbers first.
+        return NaturalStringComparer.Instance.Compare(a.DisplayName, b.DisplayName) * -1;
+
+        static int GetFamilyRank(string displayName)
+        {
+            if (displayName.StartsWith(".NET Core ", StringComparison.OrdinalIgnoreCase))
+                return 1;
+            if (displayName.StartsWith(".NET Standard ", StringComparison.OrdinalIgnoreCase))
+                return 2;
+            if (displayName.StartsWith(".NET Framework ", StringComparison.OrdinalIgnoreCase))
+                return 3;
+            if (displayName.StartsWith(".NET ", StringComparison.OrdinalIgnoreCase))
+                return 0;
+            return 4;
+        }
     }
 }