Start using OneOf<>for unions/variant

Source/Game/Entities/AreaTrigger/AreaTriggerTemplate.cs

@@ -248,8 +248,7 @@ namespace Game.Entities
         public AreaTriggerShapeInfo Shape = new();
 
         public float Speed = 1.0f;
-        public List<Vector3> SplinePoints = new();
-        public AreaTriggerOrbitInfo OrbitInfo;
+        public OneOf<EmptyStruct, List<Vector3>, AreaTriggerOrbitInfo> Movement;
 
         public uint ScriptId;
 
@@ -259,6 +258,8 @@ namespace Game.Entities
         }
     }
 
+    public struct EmptyStruct { }
+
     public class AreaTriggerSpawn : SpawnData
     {
         public new AreaTriggerId Id;