refactor: clean up launch common and add tests

[rvermootenct]

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name: Pull Request about: Create a pull request to make a contribution labels:

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IMPORTANT NOTICE: I read and understood the guidelines for contributions to the TRD. The contribution may qualify for being compensated by the TRD grant if approved by the maintainers.

This PR refactors launch common and adds tests. The following steps were performed:

• Analysis: reading through launch common fairly tough

• Solution: Split up launch common into smaller files

• Implementation: Moved all arguments for argparser to a new util file

• Performed tests: Added a bunch more tests.

Work effort: 3h

[jdsika]

Please use branches for me to do changes as well :)