Updated outdated links and adjusted for changes in BSc Informatik

[RisGar]

Partially fixes #237

Changes

Specific changes

• Changed PGdP link from Moodle to Artemis as Moodle course is not used
• Moved IT-Security from electives to third semester
• Changed 'Grundlagen: Datenbanken' link from campus.tum.de to db.in.tum.de as that page contains the slides as well as important information

General updates

• Replaced various broken in.tum.de links with equivalent cit.tum.de links
• Replaced various old course links with those of WS24/25 or SS24
  • If a course is not taught this year, the latest possible link was chosen
  • Exceptions were made when newer links contain less or no information
• Replaced broken 'AStA' links with working ones
• Removed superfluous lang=en queries

Kept as-is (for now)

• No (outdated) redirects were deleted
• No courses or links were renamed

Checklist

• I made sure that the arrays in routes.php are still alphabetically sorted. ✨ (no new links were added)

[CommanderStorm]

Thanks a ton