feat: Moves gumps out of the core (#1916)

> [!Important]
> **Developer Note**
> This code change will **completely move gumps out of the core**


### Summary

- Adds `GetGumps()` convenience which exposes methods to Find/Close/Send multiple gumps. This helper is a performance improvement by eliminating the Dictionary<Player, List> lookup for gumps.

Projects/UOContent/Engines/ConPVP/TournamentSignupItem.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using Server.Factions;
+using Server.Gumps;
 using Server.Mobiles;
 
 namespace Server.Engines.ConPVP
@@ -146,7 +147,6 @@ namespace Server.Engines.ConPVP
                             }
                             else if (!tourney.HasParticipant(from))
                             {
-                                from.CloseGump<ConfirmSignupGump>();
                                 from.SendGump(new ConfirmSignupGump(from, Registrar, tourney, new List<Mobile> { from }));
                             }
                             else