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/Gumps/ResurrectGump.cs

@@ -23,6 +23,8 @@ public class ResurrectGump : DynamicGump
     private readonly double _hitsScalar;
     private readonly ResurrectMessage _resurrectMessage;
 
+    public override bool Singleton => true;
+
     public static void TryGiveStatLoss(PlayerMobile player)
     {
         if (Core.AOS || player.ShortTermMurders < ShortMurdersForStatLoss)