Cleanup & Fixes for .NET 5 (#309)

- [X] Fixes several bugs
- [X] Updates more ordinal issues
- [X] Cleans up the code a bit
- [X] Turns classes static that should have been
- [X] Changes TcpServer.Instances to a HashSet

Bumps release version

Projects/UOContent/Commands/Dupe.cs

@@ -13,8 +13,7 @@ namespace Server.Commands
             CommandSystem.Register("DupeInBag", AccessLevel.GameMaster, DupeInBag_OnCommand);
         }
 
-        [Usage("Dupe [amount]")]
-        [Description("Dupes a targeted item.")]
+        [Usage("Dupe [amount]"), Description("Dupes a targeted item.")]
         private static void Dupe_OnCommand(CommandEventArgs e)
         {
             var amount = 1;
@@ -27,8 +26,7 @@ namespace Server.Commands
             e.Mobile.SendMessage("What do you wish to dupe?");
         }
 
-        [Usage("DupeInBag <count>")]
-        [Description("Dupes an item at it's current location (count) number of times.")]
+        [Usage("DupeInBag <count>"), Description("Dupes an item at it's current location (count) number of times.")]
         private static void DupeInBag_OnCommand(CommandEventArgs e)
         {
             var amount = 1;