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/Items/Addons/BaseAddonContainer.cs

@@ -20,8 +20,7 @@ namespace Server.Items
 
         public override bool DisplayWeight => false;
 
-        [Hue]
-        [CommandProperty(AccessLevel.GameMaster)]
+        [Hue, CommandProperty(AccessLevel.GameMaster)]
         public override int Hue
         {
             get => base.Hue;
@@ -33,8 +32,6 @@ namespace Server.Items
 
                     if (!Deleted && ShareHue && Components != null)
                     {
-                        Hue = value;
-
                         foreach (var c in Components)
                         {
                             c.Hue = value;