feat: Fixes spawner bugs with position finding, Adds [ShowSpawnerBorders (#2297)

### Summary

- Fixes BaseSpawner and Spawner bugs.
- Adds [ShowSpawnerBorders to see the spawn bounds.

Projects/UOContent/Engines/Spawners/Spawner.cs

@@ -23,6 +23,7 @@ public partial class Spawner : BaseSpawner
     private bool ShouldSerializeSpawnBounds() => _spawnBounds != default;
 
     [SerializableProperty(1)]
+    [CommandProperty(AccessLevel.Developer)]
     public override Rectangle3D SpawnBounds
     {
         get => _spawnBounds;