Core/World: implement database support for default map and realm wide world states

Port From (https://github.com/TrinityCore/TrinityCore/commit/737d94d7efe0b6c308ac1bf3692b6aa2e43f5adb)

Source/Game/Scripting/CoreScripts.cs

@@ -843,4 +843,17 @@ namespace Game.Scripting
         // Called when a quest objective data change
         public virtual void OnQuestObjectiveChange(Player player, Quest quest, QuestObjective objective, int oldAmount, int newAmount) { }
     }
+
+    public class WorldStateScript : ScriptObject
+    {
+        public WorldStateScript(string name) : base(name)
+        {
+            Global.ScriptMgr.AddScript(this);
+        }
+
+        public override bool IsDatabaseBound() { return true; }
+
+        // Called when worldstate changes value, map is optional
+        public virtual void OnValueChange(int worldStateId, int oldValue, int newValue, Map map) { }
+    }
 }

Source/Game/Scripting/ScriptManager.cs

@@ -1198,6 +1198,14 @@ namespace Game.Scripting
             RunScript<QuestScript>(script => script.OnQuestObjectiveChange(player, quest, objective, oldAmount, newAmount), quest.ScriptId);
         }
 
+        // WorldState
+        public void OnWorldStateValueChange(WorldStateTemplate worldStateTemplate, int oldValue, int newValue, Map map)
+        {
+            Cypher.Assert(worldStateTemplate != null);
+
+            RunScript<WorldStateScript>(script => script.OnValueChange(worldStateTemplate.Id, oldValue, newValue, map), worldStateTemplate.ScriptId);
+        }
+        
         public void ForEach<T>(Action<T> a) where T : ScriptObject
         {
             var reg = GetScriptRegistry<T>();