Added aliases for Symfony4 service autowiring

[romaricdrigon]

Hello,

This PR adds some aliases so Symfony4 autowiring works out of the box.
Still it keep old service names, so there's no BC break.

It fixes #857

Example of autowiring :

class MyController extends AbstractController
{
    /**
     * @Route("/test", name="test_index")
     */
    public function index(DatatableFactory $factory, DatatableResponse $datatableResponse, Request $request)
    {
       $datatable = $factory->create(PostDatatable::class);
        $datatable->buildDatatable();

        if ($request->isXmlHttpRequest()) {
            $datatableResponse->setDatatable($datatable);
            $datatableResponse->getDatatableQueryBuilder();

            return $datatableResponse->getResponse();
        }

      return $this->render('post/index.html.twig', array(
            'datatable' => $datatable,
      ));
    }
}