Core/AI: Kick Gossip functions upstairs, from UnitAI to CreatureAI - they only make sense for Creatures anyway.

Port From (https://github.com/TrinityCore/TrinityCore/commit/0aed5a35efd0305c1c3046430a1b348f2049a1c5)

Source/Game/AI/CoreAI/GameObjectAI.cs

@@ -47,6 +47,11 @@ namespace Game.AI
         public virtual void SetGUID(ObjectGuid guid, int id = 0) { }
         public virtual ObjectGuid GetGUID(int id = 0) { return ObjectGuid.Empty; }
 
+        /// <summary>
+        /// Called when the dialog status between a player and the gameobject is requested.
+        /// </summary>
+        public virtual QuestGiverStatus? GetDialogStatus(Player player) { return null; }
+
         /// <summary>
         /// Called when a player opens a gossip dialog with the gameobject.
         /// </summary>
@@ -76,11 +81,6 @@ namespace Game.AI
         }
         public virtual void QuestReward(Player player, Quest quest, LootItemType type, uint opt) { }
 
-        /// <summary>
-        /// Called when the dialog status between a player and the gameobject is requested.
-        /// </summary>
-        public virtual QuestGiverStatus GetDialogStatus(Player player) { return QuestGiverStatus.ScriptedDefault; }
-
         // Called when a Player clicks a GameObject, before GossipHello
         // prevents achievement tracking if returning true
         public virtual bool OnReportUse(Player player) { return false; }