Improve check-code-style.sh

Create a rule set section similar to doc.zih.tu-dresden.de/util/grep-forbidden-patterns.sh. This improves #340 (closed).

TODO:

• Improve workflow on
  • how to ignore certain files for checking and in general to
  • making it more compact and maintainable when the number of rules increase
• Extend the script to other programming languages
  • Shell (add some more rules if any)
  • Python (e. g. https://pypi.org/project/pylint/, https://flake8.pycqa.org/en/latest/index.html#quickstart)
  • R
  • ??