Core/Items: Item bonus generation improvements

* Pass ItemContext to item creation wherever possible
* Support scaling item levels with m+ keystone levels (not used currently)
* Fixed item link validation when client sends it as default uninitialized bonus list with context only
* Support scaling items depending on current active season (seasons not implemented)
* Implemented content tuning redirection
Port From (https://github.com/TrinityCore/TrinityCore/commit/0fb8765a6638fd947b59fce44d5c31251d0cdadd)

Source/Game/Entities/Item/ItemEnchantment.cs

@@ -32,7 +32,7 @@ namespace Game.Entities
                 uint bonusListId = result.Read<uint>(1);
                 float chance = result.Read<float>(2);
 
-                if (Global.DB2Mgr.GetItemBonusList(bonusListId) == null)
+                if (ItemBonusMgr.GetItemBonuses(bonusListId).Empty())
                 {
                     Log.outError(LogFilter.Sql, $"Bonus list {bonusListId} used in `item_random_bonus_list_template` by id {id} doesn't have exist in ItemBonus.db2");
                     continue;