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

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

Source/Game/World/WorldManager.cs

@@ -514,8 +514,8 @@ namespace Game
 
             // Must be called before `respawn` data
             Log.outInfo(LogFilter.ServerLoading, "Loading instances...");
-            Global.InstanceSaveMgr.LoadInstances();
 
+            Global.MapMgr.InitInstanceIds();
             Global.InstanceLockMgr.Load();
 
             Log.outInfo(LogFilter.ServerLoading, "Loading Localization strings...");
@@ -1493,9 +1493,6 @@ namespace Game
                 Global.GuildMgr.SaveGuilds();
             }
 
-            // update the instance reset times
-            Global.InstanceSaveMgr.Update();
-
             // Check for shutdown warning
             if (_guidWarn && !_guidAlert)
             {