N°8771 - Add Symfony form component to iTop core (#760)

- Add Symfony Form Component
- Add Symfony CSRF security component
- Add iTop default form template
- Add Twig debug extension to Twig Environment
- Add iTop abstract controller facility to get form builder
- Add Twig filter to make trans an alias of dict_s filter

lib/symfony/form/Util/InheritDataAwareIterator.php

@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Util;
+
+/**
+ * Iterator that traverses an array of forms.
+ *
+ * Contrary to \ArrayIterator, this iterator recognizes changes in the original
+ * array during iteration.
+ *
+ * You can wrap the iterator into a {@link \RecursiveIteratorIterator} in order to
+ * enter any child form that inherits its parent's data and iterate the children
+ * of that form as well.
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class InheritDataAwareIterator extends \IteratorIterator implements \RecursiveIterator
+{
+    public function getChildren(): static
+    {
+        return new static($this->current());
+    }
+
+    public function hasChildren(): bool
+    {
+        return (bool) $this->current()->getConfig()->getInheritData();
+    }
+}