Quality of RWTH

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
- Adds a button to download OpenCast videos which can usually not 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.