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/console/Completion/CompletionSuggestions.php

@@ -0,0 +1,99 @@
+<?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\Console\Completion;
+
+use Symfony\Component\Console\Input\InputOption;
+
+/**
+ * Stores all completion suggestions for the current input.
+ *
+ * @author Wouter de Jong <wouter@wouterj.nl>
+ */
+final class CompletionSuggestions
+{
+    private $valueSuggestions = [];
+    private $optionSuggestions = [];
+
+    /**
+     * Add a suggested value for an input option or argument.
+     *
+     * @param string|Suggestion $value
+     *
+     * @return $this
+     */
+    public function suggestValue($value): self
+    {
+        $this->valueSuggestions[] = !$value instanceof Suggestion ? new Suggestion($value) : $value;
+
+        return $this;
+    }
+
+    /**
+     * Add multiple suggested values at once for an input option or argument.
+     *
+     * @param list<string|Suggestion> $values
+     *
+     * @return $this
+     */
+    public function suggestValues(array $values): self
+    {
+        foreach ($values as $value) {
+            $this->suggestValue($value);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Add a suggestion for an input option name.
+     *
+     * @return $this
+     */
+    public function suggestOption(InputOption $option): self
+    {
+        $this->optionSuggestions[] = $option;
+
+        return $this;
+    }
+
+    /**
+     * Add multiple suggestions for input option names at once.
+     *
+     * @param InputOption[] $options
+     *
+     * @return $this
+     */
+    public function suggestOptions(array $options): self
+    {
+        foreach ($options as $option) {
+            $this->suggestOption($option);
+        }
+
+        return $this;
+    }
+
+    /**
+     * @return InputOption[]
+     */
+    public function getOptionSuggestions(): array
+    {
+        return $this->optionSuggestions;
+    }
+
+    /**
+     * @return Suggestion[]
+     */
+    public function getValueSuggestions(): array
+    {
+        return $this->valueSuggestions;
+    }
+}