Core/Creature: Added possibility to give creatures multiple gossip menu ids and control them via conditions

Port From (https://github.com/TrinityCore/TrinityCore/commit/36044a9470e9c39a71916e908ab6cf4f95677793)

Source/Game/Handlers/NPCHandler.cs

@@ -153,7 +153,7 @@ namespace Game
             _player.PlayerTalkClass.ClearMenus();
             if (!unit.GetAI().OnGossipHello(_player))
             {
-                GetPlayer().PrepareGossipMenu(unit, unit.GetGossipMenuId(), true);
+                GetPlayer().PrepareGossipMenu(unit, _player.GetGossipMenuForSource(unit), true);
                 GetPlayer().SendPreparedGossip(unit);
             }
         }

Source/Game/Handlers/QuestHandler.cs

@@ -68,7 +68,7 @@ namespace Game
             if (creature.GetAI().OnGossipHello(_player))
                 return;
 
-            GetPlayer().PrepareGossipMenu(creature, creature.GetGossipMenuId(), true);
+            GetPlayer().PrepareGossipMenu(creature, _player.GetGossipMenuForSource(creature), true);
             GetPlayer().SendPreparedGossip(creature);
         }