Core/Instances: Delete InstanceSaveMgr and replace most of its uses with new InstanceLockMgr

Port From (https://github.com/TrinityCore/TrinityCore/commit/9b924522d0549dd67b10e2cbdfc20297dd21e182)

Source/Game/Entities/Player/Player.Fields.cs

@@ -78,7 +78,6 @@ namespace Game.Entities
         bool m_bPassOnGroupLoot;
         GroupUpdateCounter[] m_groupUpdateSequences = new GroupUpdateCounter[2];
 
-        public Dictionary<Difficulty, Dictionary<uint, InstanceBind>> m_boundInstances = new();
         Dictionary<uint, uint> m_recentInstances = new();
         Dictionary<uint, long> _instanceResetTimes = new();
         uint _pendingBindId;