Core/Spells: Handle GAMEOBJECT_TYPE_UI_LINK spellFocus

Port From (https://github.com/TrinityCore/TrinityCore/commit/97afa3a609923bd9b7c0e9cfc52c29ba9dbfe35d)

Source/Game/Entities/GameObject/GameObjectData.cs

@@ -517,6 +517,32 @@ namespace Game.Entities
             }
         }
 
+        public uint GetSpellFocusType()
+        {
+            switch (type)
+            {
+                case GameObjectTypes.SpellFocus:
+                    return SpellFocus.spellFocusType;
+                case GameObjectTypes.UILink:
+                    return UILink.spellFocusType;
+                default:
+                    return 0;
+            }
+        }
+
+        public uint GetSpellFocusRadius()
+        {
+            switch (type)
+            {
+                case GameObjectTypes.SpellFocus:
+                    return SpellFocus.radius;
+                case GameObjectTypes.UILink:
+                    return UILink.radius;
+                default:
+                    return 0;
+            }
+        }
+
         public void InitializeQueryData()
         {
             QueryData = new QueryGameObjectResponse();

Source/Game/Maps/GridNotifiers.cs

@@ -2247,16 +2247,13 @@ namespace Game.Maps
 
         public bool Invoke(GameObject go)
         {
-            if (go.GetGoInfo().type != GameObjectTypes.SpellFocus)
-                return false;
-
-            if (go.GetGoInfo().SpellFocus.spellFocusType != i_focusId)
+            if (go.GetGoInfo().GetSpellFocusType() != i_focusId)
                 return false;
 
             if (!go.IsSpawned())
                 return false;
 
-            float dist = go.GetGoInfo().SpellFocus.radius / 2.0f;
+            float dist = go.GetGoInfo().GetSpellFocusRadius() / 2.0f;
 
             return go.IsWithinDistInMap(i_unit, dist);
         }