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/ChoiceList/Loader/IntlCallbackChoiceLoader.php

@@ -0,0 +1,38 @@
+<?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\ChoiceList\Loader;
+
+/**
+ * Callback choice loader optimized for Intl choice types.
+ *
+ * @author Jules Pietri <jules@heahprod.com>
+ * @author Yonel Ceruto <yonelceruto@gmail.com>
+ */
+class IntlCallbackChoiceLoader extends CallbackChoiceLoader
+{
+    public function loadChoicesForValues(array $values, ?callable $value = null): array
+    {
+        return parent::loadChoicesForValues(array_filter($values), $value);
+    }
+
+    public function loadValuesForChoices(array $choices, ?callable $value = null): array
+    {
+        $choices = array_filter($choices);
+
+        // If no callable is set, choices are the same as values
+        if (null === $value) {
+            return $choices;
+        }
+
+        return parent::loadValuesForChoices($choices, $value);
+    }
+}