Core/AI: Make charmed creatures follow their owner

Port From (https://github.com/TrinityCore/TrinityCore/commit/144cfc2bcebbd0d2bbce5f97a06f634d17d62e79)

Source/Game/AI/CoreAI/PetAI.cs

@@ -623,6 +623,14 @@ namespace Game.AI
                 _allySet.Add(owner.GetGUID());
         }
 
+        public override void OnCharmed(bool isNew)
+        {
+            if (me.IsCharmed())
+                me.GetMotionMaster().MoveFollow(me.GetCharmer(), SharedConst.PetFollowDist, me.GetFollowAngle());
+
+            base.OnCharmed(isNew);
+        }
+
         void ClearCharmInfoFlags()
         {
             // Quick access to set all flags to FALSE

Source/Game/AI/SmartScripts/SmartAI.cs

@@ -741,6 +741,9 @@ namespace Game.AI
 
             _isCharmed = charmed;
 
+            if (charmed)
+                me.GetMotionMaster().MoveFollow(me.GetCharmer(), SharedConst.PetFollowDist, me.GetFollowAngle());
+
             if (!charmed && !me.IsInEvadeMode())
             {
                 if (_repeatWaypointPath)