perf: Migrate HouseGump to DynamicGump (#2428)

## Summary
- Converts the legacy pre-AOS `HouseGump` to `DynamicGump` with a private constructor and the static `DisplayTo` entry-point pattern.
- `HouseListGump` and `HouseRemoveGump` now route back through `HouseGump.DisplayTo` instead of constructing the gump directly.
- Updates the `HouseSign` caller accordingly.

Projects/UOContent/Multis/Houses/HouseSign.cs

@@ -132,7 +132,7 @@ public partial class HouseSign : Item
         }
         else
         {
-            m.SendGump(new HouseGump(m, Owner));
+            HouseGump.DisplayTo(m, Owner);
         }
     }