[CodeQuality] Add CompactToVariablesRector

[TomasVotruba]

Closes #1379

$checkout = checkout();
$form     = $this->createForm(DeliveryType::class, DeliveryData::createFrom($checkout))->createView();

-return $this->render('@FrontendBundle/checkout/delivery.html.twig', compact('checkout', 'form'));
+return $this->render('@FrontendBundle/checkout/delivery.html.twig', [
+    'checkout' => $checkout,
+    'form' => $form,
+]);