migration symfony 5 4 (#300)

* symfony 5.4 (diff dev)

* symfony 5.4 (working)

* symfony 5.4 (update autoload)

* symfony 5.4 (remove swiftmailer mailer implementation)

* symfony 5.4 (php doc and split Global accessor class)


### Impacted packages:

composer require php:">=7.2.5 <8.0.0" symfony/console:5.4.* symfony/dotenv:5.4.* symfony/framework-bundle:5.4.* symfony/twig-bundle:5.4.* symfony/yaml:5.4.* --update-with-dependencies

composer require symfony/stopwatch:5.4.* symfony/web-profiler-bundle:5.4.* --dev --update-with-dependencies

lib/symfony/cache/Marshaller/DeflateMarshaller.php

@@ -0,0 +1,53 @@
+<?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\Cache\Marshaller;
+
+use Symfony\Component\Cache\Exception\CacheException;
+
+/**
+ * Compresses values using gzdeflate().
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class DeflateMarshaller implements MarshallerInterface
+{
+    private $marshaller;
+
+    public function __construct(MarshallerInterface $marshaller)
+    {
+        if (!\function_exists('gzdeflate')) {
+            throw new CacheException('The "zlib" PHP extension is not loaded.');
+        }
+
+        $this->marshaller = $marshaller;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function marshall(array $values, ?array &$failed): array
+    {
+        return array_map('gzdeflate', $this->marshaller->marshall($values, $failed));
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function unmarshall(string $value)
+    {
+        if (false !== $inflatedValue = @gzinflate($value)) {
+            $value = $inflatedValue;
+        }
+
+        return $this->marshaller->unmarshall($value);
+    }
+}