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/Server.Tests/Tests/Gumps/TestGumps/StaticTestGump.cs

@@ -1,32 +0,0 @@
-using Server.Gumps;
-
-namespace Server.Tests.Gumps;
-
-public class StaticTestGump : StaticGump<StaticTestGump>
-{
-    public StaticTestGump() : base(50, 50)
-    {
-        Serial = (Serial)0x123;
-        TypeID = 0x5345;
-    }
-
-    protected override void BuildLayout(ref StaticGumpBuilder builder)
-    {
-        builder.AddPage();
-
-        builder.AddBackground(10, 10, 265, 140, 0x242C);
-
-        builder.AddItem(205, 40, 0x4);
-        builder.AddItem(227, 40, 0x5);
-
-        builder.AddItem(180, 78, 0xCAE);
-        builder.AddItem(195, 90, 0xCAD);
-        builder.AddItem(218, 95, 0xCB0);
-
-        builder.AddHtml(30, 30, 150, 75, "<div align=center>Wilt thou sanctify the resurrection of:</div>");
-        builder.AddHtml(30, 70, 150, 25, "<CENTER>Test</CENTER>", true);
-
-        builder.AddButton(40, 105, 0x81A, 0x81B, 0x1);  // Okay
-        builder.AddButton(110, 105, 0x819, 0x818, 0x2); // Cancel
-    }
-}