Moved ScriptMgr macros to separated header and created ModuleScript

it will allow Modules to create their own Hooks inside the
module itself, to customize/extend their functionalities.

An example of its usage will be available in VAS Module:
You'll be able to disable VAS with custom conditions from other modules.

src/server/game/Scripting/ScriptMgr.h

@@ -1017,6 +1017,15 @@ class GlobalScript : public ScriptObject
         virtual void OnBeforeUpdateArenaPoints(ArenaTeam* /*at*/, std::map<uint32, uint32> & /*ap*/) { }
 };
 
+// this class can be used to be extended by Modules
+// creating their own custom hooks inside module itself
+class ModuleScript : public ScriptObject
+{
+    protected:
+
+        ModuleScript(const char* name);
+};
+
 // Placed here due to ScriptRegistry::AddScript dependency.
 #define sScriptMgr ACE_Singleton<ScriptMgr, ACE_Null_Mutex>::instance()
 
@@ -1460,4 +1469,9 @@ class ScriptRegistry
         static uint32 _scriptIdCounter;
 };
 
+// Instantiate static members of ScriptRegistry.
+template<class TScript> std::map<uint32, TScript*> ScriptRegistry<TScript>::ScriptPointerList;
+template<class TScript> std::vector<TScript*> ScriptRegistry<TScript>::ALScripts;
+template<class TScript> uint32 ScriptRegistry<TScript>::_scriptIdCounter = 0;
+
 #endif