[WebProfilerBundle] [FrameworkBundle] profile forward controller action

closes #14358

The `Symfony\Bundle\FrameworkBundle\Controller\Controller::forward()`
now passes request attributes to its sub request, so when the profiler
will profile the sub request it will add its token to its hold by
reference parent request attributes.

The profiler main profiler layout displays a shortcut to the forwarded
sub request profile which is actually responsible for returning the
present response.

The web debug toolbar shows a notifying icon, meaning a shortcut to a
forwarded profile is available in the toolbar request panel.

Author: HeahDude

Controller/Controller.php

@@ -65,8 +65,10 @@ protected function generateUrl($route, $parameters = array(), $referenceType = U
      */
     protected function forward($controller, array $path = array(), array $query = array())
     {
+        $request = $this->container->get('request_stack')->getCurrentRequest();
+        $path['_forwarded'] = $request->attributes;
         $path['_controller'] = $controller;
-        $subRequest = $this->container->get('request_stack')->getCurrentRequest()->duplicate($query, null, $path);
+        $subRequest = $request->duplicate($query, null, $path);
 
         return $this->container->get('http_kernel')->handle($subRequest, HttpKernelInterface::SUB_REQUEST);
     }