Add Symfony container support for Rector configuration

- Introduced `tests/symfony-container.php` for bootstrapping Symfony.
  - Updated `rector.php` with new container PHP path and kernel modifications.
  - Registered Symfony routes provider service in Rector.

tests/symfony-container.php

@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+use Tvdt\Kernel;
+
+require __DIR__.'/bootstrap.php';
+
+$appKernel = new Kernel('test', false);
+$appKernel->boot();
+
+return $appKernel->getContainer();