feat: Adds KR/EC client versions (No actual support yet). (#1506)

### Summary

- Adds KR/EC client versions to ClientVersion
- Adds distinction for enhanced versions in the page queue
- Adds KR Expansion flags
- Adds ProtocolChange enum support
- Adds missing Moongate checks for TerMur
- Adds better message for why a client version is not supported, and which ones are supported.

Projects/UOContent/Gumps/ClientGump.cs

@@ -44,7 +44,7 @@ namespace Server.Gumps
                 36 + line++ * 20,
                 200,
                 20,
-                Color(state.Version?.SourceString ?? "(null)", LabelColor32)
+                Color(state.Version?.ToString().DefaultIfNullOrEmpty("(null)"), LabelColor32)
             );
 
             AddHtml(14, 36 + line * 20, 200, 20, Color("Assistant:", LabelColor32));