Core/Units: Added helper methods to cancel mount/shapeshift auras

Port From (https://github.com/TrinityCore/TrinityCore/commit/0b16756172b2c3cc78b0861af86b93daae60edda)

Source/Game/Entities/Unit/Unit.Movement.cs

@@ -938,6 +938,18 @@ namespace Game.Entities
             return true;
         }
 
+        void CancelMountAura(bool force)
+        {
+            if (!HasAuraType(AuraType.Mounted))
+                return;
+
+            RemoveAurasByType(AuraType.Mounted, aurApp =>
+            {
+                SpellInfo spellInfo = aurApp.GetBase().GetSpellInfo();
+                return force || (!spellInfo.HasAttribute(SpellAttr0.NoAuraCancel) && spellInfo.IsPositive() && !spellInfo.IsPassive());
+            });
+        }
+
         public MountCapabilityRecord GetMountCapability(uint mountType)
         {
             if (mountType == 0)
@@ -1043,6 +1055,14 @@ namespace Game.Entities
             if (IsLoading())
                 return;
 
+            var spellShapeshiftForm = CliDB.SpellShapeshiftFormStorage.LookupByKey(GetShapeshiftForm());
+            if (spellShapeshiftForm != null)
+            {
+                uint mountType = spellShapeshiftForm.MountTypeID;
+                if (mountType != 0 && GetMountCapability(mountType) == null)
+                    CancelTravelShapeshiftForm(AuraRemoveMode.Interrupt);
+            }
+
             var mounts = GetAuraEffectsByType(AuraType.Mounted);
             foreach (AuraEffect aurEff in mounts.ToArray())
             {