Core/Game: Move scheduled map scripts counter methods into MapManager

* Since those have nothing to do with core scripts and are
  not wished inside the ScriptMgr

src/server/game/Scripting/ScriptMgr.h

@@ -1102,19 +1102,9 @@ class TC_GAME_API ScriptMgr
         void ModifyMeleeDamage(Unit* target, Unit* attacker, uint32& damage);
         void ModifySpellDamageTaken(Unit* target, Unit* attacker, int32& damage);
 
-    public: /* Scheduled scripts */
-
-        uint32 IncreaseScheduledScriptsCount() { return ++_scheduledScripts; }
-        uint32 DecreaseScheduledScriptCount() { return --_scheduledScripts; }
-        uint32 DecreaseScheduledScriptCount(size_t count) { return _scheduledScripts -= count; }
-        bool IsScriptScheduled() const { return _scheduledScripts > 0; }
-
     private:
         uint32 _scriptCount;
 
-        //atomic op counter for active scripts amount
-        std::atomic<uint32> _scheduledScripts;
-
         ScriptLoaderCallbackType _script_loader_callback;
 
         std::string _currentContext;