Core/World: Allow specifying minimum world updates diff in config

Port From (https://github.com/TrinityCore/TrinityCore/commit/833ddfad11fdb6af37bb70296dbc11613f4d0f5f)

Source/WorldServer/Server.cs

@@ -180,6 +180,7 @@ namespace WorldServer
 
         static void WorldUpdateLoop()
         {
+            int minUpdateDiff = ConfigMgr.GetDefaultValue("MinWorldUpdateTime", 1);
             uint realPrevTime = Time.GetMSTime();
 
             while (!Global.WorldMgr.IsStopped)
@@ -187,10 +188,10 @@ namespace WorldServer
                 var realCurrTime = Time.GetMSTime();
 
                 uint diff = Time.GetMSTimeDiff(realPrevTime, realCurrTime);
-                if (diff == 0)
+                if (diff < minUpdateDiff)
                 {
                     // sleep until enough time passes that we can update all timers
-                    Thread.Sleep(1);
+                    Thread.Sleep(TimeSpan.FromMilliseconds(minUpdateDiff - diff));
                     continue;
                 }
 

Source/WorldServer/WorldServer.conf.dist

@@ -331,6 +331,13 @@ SessionAddDelay = 10000
 
 GridCleanUpDelay = 300000
 
+#
+#    MinWorldUpdateTime
+#        Description: Minimum time (milliseconds) between world update ticks (for mostly idle servers).
+#        Default:     1 - (0.001 second)
+
+MinWorldUpdateTime = 1
+
 #
 #    MapUpdateInterval
 #        Description: Time (milliseconds) for map update interval.