Fix CI

After getting new runners from the IT Service, the pipeline seemed to not be stuck anymore but failed.

Necessary adjustments were:

• applying clang-format rules to all developer scripts
• adjusting main function of FisherKPP homework (see d7b87a1a) to not require a runtime input.
  This was necessary because test-developer-job-[mac/linux] run all mastersolutions with a shell script and would otherwise get stuck on the input prompt. I felt that this was the simplest solution.

Some Notes:

• added a basic script in scripts folder that automatically applies clang-format rules to all developer files
• The pipeline took rough 90min, 60min were compilation
• Important: None of the developer files have been deployed to the homeworks folder!