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/security-csrf/TokenGenerator/TokenGeneratorInterface.php

@@ -0,0 +1,25 @@
+<?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\Security\Csrf\TokenGenerator;
+
+/**
+ * Generates CSRF tokens.
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+interface TokenGeneratorInterface
+{
+    /**
+     * Generates a CSRF token.
+     */
+    public function generateToken(): string;
+}

lib/symfony/security-csrf/TokenGenerator/UriSafeTokenGenerator.php

@@ -0,0 +1,46 @@
+<?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\Security\Csrf\TokenGenerator;
+
+/**
+ * Generates CSRF tokens.
+ *
+ * @author Bernhard Schussek <bernhard.schussek@symfony.com>
+ */
+class UriSafeTokenGenerator implements TokenGeneratorInterface
+{
+    private int $entropy;
+
+    /**
+     * Generates URI-safe CSRF tokens.
+     *
+     * @param int $entropy The amount of entropy collected for each token (in bits)
+     */
+    public function __construct(int $entropy = 256)
+    {
+        if ($entropy <= 7) {
+            throw new \InvalidArgumentException('Entropy should be greater than 7.');
+        }
+
+        $this->entropy = $entropy;
+    }
+
+    public function generateToken(): string
+    {
+        // Generate an URI safe base64 encoded string that does not contain "+",
+        // "/" or "=" which need to be URL encoded and make URLs unnecessarily
+        // longer.
+        $bytes = random_bytes(intdiv($this->entropy, 8));
+
+        return rtrim(strtr(base64_encode($bytes), '+/', '-_'), '=');
+    }
+}