Refactor authentication system (#2602)

Make auth configuration available via UI, remove FOSUserBundle and SAML-Bundle dependency

src/Event/UserUpdatePreEvent.php

@@ -0,0 +1,17 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Event;
+
+/**
+ * Triggered for user instances, which are about to be updated.
+ */
+final class UserUpdatePreEvent extends AbstractUserEvent
+{
+}