Add multiple groups per "patient"

[votti]

For Crispr off target effects we need to do the variant calling for each sample to the parental cell line. I would propose to encode this in the units:

patient_id = parental cell line
sample = normal (=reference) or other sample name

[votti]

Looking more into this: maybe it will be better to use https://nf-co.re/sarek/3.4.0 to begin with