v3.8.3

Improvements:

• Confirm course registration for PGdP course
• Save course registration events in audit log of the database to make them easier to trace
• Only allow manual results in programming exercises if the corresponding setting is activated
• Add grading instructions to programming exercise dialog if manual results are activated
• Improve wording and layout in participations page
• Provide guided tour tutorial videos in German and English in an improved quality

Bugfixes:

• Make sure "Select a course" is shown during course registration
• Start exercise for programming exercises did not work in rare cases. Now it should be more reliable
• Fix several translation issues
• Fix styling issues of problem statement, grading instructions, etc. in tutor exercise dashboard