Quality of RWTH troch Leon Müller

Adds some quality-of-life features to the RWTH websites, particularly to RWTHMoodle, mainly:

• Auto-forward from unnecessary pre-login pages
• Skip the incredibly slow PDF annotator and just display the PDF directly (can be disabled like all features)
• Adds a menu in the toolbar to quickly navigate to all courses, to avoid having to wait for hours for the Moodle dashboard to load. CTRL-click to open a page inside the popup window. (Click the icon extension icon or press ALT+R)
• Adds a button to download OpenCast videos which cannot be downloaded directly from the moodle page

I'm not usually coding in JS or HTML, so don't expect any masterpiece, particularly not in terms of design. Form follows function.