Core/Player: Prevent changing equipment while charmed.

Port From (https://github.com/TrinityCore/TrinityCore/commit/fc12e47cb8e3f4c1097b41e94a92151776818717)

Source/Game/Entities/Player/Player.Items.cs

@@ -5172,6 +5172,9 @@ namespace Game.Entities
                         if (HasUnitState(UnitState.Stunned))
                             return InventoryResult.GenericStunned;
 
+                        if (IsCharmed())
+                            return InventoryResult.CantDoThatRightNow; // @todo is this the correct error?
+
                         // do not allow equipping gear except weapons, offhands, projectiles, relics in
                         // - combat
                         // - in-progress arenas
@@ -5405,6 +5408,9 @@ namespace Game.Entities
             if (pItem.m_lootGenerated)
                 return InventoryResult.LootGone;
 
+            if (IsCharmed())
+                return InventoryResult.CantDoThatRightNow; // @todo is this the correct error?
+
             // do not allow unequipping gear except weapons, offhands, projectiles, relics in
             // - combat
             // - in-progress arenas