feat: Changes Spawner HomeRange to SpawnBounds (#2290)

### Summary

This PR transitions the spawner system from a simple radius-based model to a flexible 3D boundary system.

### Core Changes

* **Replaced `HomeRange` with `SpawnBounds`**: Spawners now use a `Rectangle3D` to define spawn areas instead of a circular integer range.
* **Backward Compatibility**:
* The `HomeRange` property remains as a helper that generates square `SpawnBounds` centered on the spawner.
* Included a migration path (v10 to v11) that automatically converts old range data into new bounds during deserialization.


* **Dynamic Bounds Shifting**: If a spawner is moved, its `SpawnBounds` will automatically shift with it, provided the bounds are currently configured as a centered square.
* **New Spawn Logic**: Added `SpawnLocationIsHome` toggle. If enabled, spawned mobiles treat their exact spawn coordinates as their "Home" rather than the spawner's location.

### Implementation Details

* **Interface Updates**: Updated `ISpawner` to include `WalkingRange`, `SpawnBounds`, and `IsInSpawnBounds()`.
* **UI Enhancements**: The Spawner Controller Gump now displays "Custom" for complex bounds and allows copying of the new boundary properties between spawners.
* **Refactored Constructors**: Streamlined `BaseSpawner`, `ProximitySpawner`, and `RegionSpawner` constructors to support the new data types.

Projects/UOContent/Migrations/Server.Engines.Spawners.BaseSpawner.v11.json

@@ -0,0 +1,108 @@
+{
+  "version": 11,
+  "type": "Server.Engines.Spawners.BaseSpawner",
+  "properties": [
+    {
+      "name": "Guid",
+      "type": "System.Guid",
+      "rule": "PrimitiveTypeMigrationRule"
+    },
+    {
+      "name": "ReturnOnDeactivate",
+      "type": "bool",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "Entries",
+      "type": "System.Collections.Generic.List\u003CServer.Engines.Spawners.SpawnerEntry\u003E",
+      "rule": "ListMigrationRule",
+      "ruleArguments": [
+        "Server.Engines.Spawners.SpawnerEntry",
+        "RawSerializableMigrationRule",
+        "DeserializationRequiresParent"
+      ]
+    },
+    {
+      "name": "WalkingRange",
+      "type": "int",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "WayPoint",
+      "type": "Server.Items.WayPoint",
+      "rule": "SerializableInterfaceMigrationRule"
+    },
+    {
+      "name": "Group",
+      "type": "bool",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "MinDelay",
+      "type": "System.TimeSpan",
+      "rule": "PrimitiveTypeMigrationRule"
+    },
+    {
+      "name": "MaxDelay",
+      "type": "System.TimeSpan",
+      "rule": "PrimitiveTypeMigrationRule"
+    },
+    {
+      "name": "Count",
+      "type": "int",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "Team",
+      "type": "int",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "SpawnBounds",
+      "type": "Server.Rectangle3D",
+      "rule": "PrimitiveUOTypeMigrationRule",
+      "ruleArguments": [
+        "Rect3D"
+      ]
+    },
+    {
+      "name": "Running",
+      "type": "bool",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "SpawnLocationIsHome",
+      "type": "bool",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    },
+    {
+      "name": "End",
+      "type": "System.DateTime",
+      "rule": "PrimitiveTypeMigrationRule",
+      "ruleArguments": [
+        ""
+      ]
+    }
+  ]
+}