move custom validation to groovy

[RobJY]

Description of feature

move bin/check_marker_sheet.py and bin/check_sample_and_marker_sheet.py to groovy

[josenimo]

Hey Rob, by moving it to groovy, what do you mean?
I assume it means converting the local modules into fully fledged nf-core modules?

[RobJY]

Yes, that's correct

[jmuhlich]

Not converting to full nf-core modules, but rather converting from python scripts that run as separate (local) modules in the workflow into .nf scripts that run as part of the workflow itself (see subworkflows/local/utils_nfcore_mcmicro_pipeline/main.nf).

[RobJY]

I have updated code for this in my fork in branch 'input_validation'. I'll make a PR once #29 has been merged.
It still needs a little work. I'm unsure about how to proceed in a few places, so we can discuss that and any changes you'd like in the PR.