fix: Upgrade TranslatableStringHelper service and create its interface.

src/Bundle/ChillMainBundle/Templating/TranslatableStringHelperInterface.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chill\MainBundle\Templating;
+
+interface TranslatableStringHelperInterface
+{
+    /**
+     * Return the string in current locale if it exists.
+     *
+     * If it does not exists; return the name in the first language available.
+     *
+     * Return a blank string if any strings are available.
+     */
+    public function localize(array $translatableStrings): ?string;
+}