Draft: be able to inject middlewares from configuration

lib/cartodb/api/map/map-router.js

@@ -126,9 +126,11 @@ module.exports = class MapRouter {
         );
     }
 
-    register (apiRouter, mapPaths) {
+    register (apiRouter, mapPaths, mapMiddlewares = []) {
         const mapRouter = router({ mergeParams: true });
 
+        mapMiddlewares.forEach(middleware => mapRouter.use(middleware()));
+
         this.analysisLayergroupController.register(mapRouter);
         this.attributesLayergroupController.register(mapRouter);
         this.dataviewLayergroupController.register(mapRouter);