Make magi_workflow --help function more informative

[hleegwater]

I want the help function to produce more informative information so that a user can just type magi_workflow.py --help and from that knows what to do. The help function does not crash anymore (previously fixed in branch fix-help) but it can be better.

[hleegwater]

Move the check where either -c or -f needs to be provided to the argparse.

[hleegwater]

Find out if --test and --debug are still needed