Codechange: [Script] do not redefine types in the script API

Also move includes to the locations where they are actually used

src/script/api/script_vehicle.hpp

@@ -11,6 +11,8 @@
 #define SCRIPT_VEHICLE_HPP
 
 #include "script_road.hpp"
+#include "../../engine_type.h"
+#include "../../group_type.h"
 
 /**
  * Class that handles all vehicle related functions.