remove obsolete tools navigation, fixes #4709

Closes #4709

Merge request studip/studip!3502

lib/navigation/ToolsNavigation.php

-<?php
-# Lifter010: TODO
-/*
- * ToolsNavigation.php - navigation for tools page
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * @author      Elmar Ludwig
- * @author      Michael Riehemann <michael.riehemann@uni-oldenburg.de>
- * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
- * @category    Stud.IP
- * @since       2.0
- */
-
-/**
- * This navigation includes all tools for a user depending on the
- * activated modules.
- */
-class ToolsNavigation extends Navigation
-{
-    /**
-     * Initialize a new Navigation instance.
-     */
-    public function __construct()
-    {
-        parent::__construct(_('Tools'));
-
-        $this->setImage(Icon::create('tools', 'navigation', ["title" => _('Tools')]));
-    }
-
-    /**
-     * Initialize the subnavigation of this item. This method
-     * is called once before the first item is added or removed.
-     */
-    public function initSubNavigation()
-    {
-        global $auth, $perm;
-
-        parent::initSubNavigation();
-
-    }
-}