Expand `.splitCsv()` to allow comments in CSV and TSV files

[nvnieuwk]

New feature

Someone opened a feature request on nf-schema to ask to allow comments (#) in CSV and TSV files. I however think this would be an awesome upstream addition to the .splitCsv() method so everyone can benefit from that feature. Comments syntax as explained here makes the most sense I think: https://www.w3schools.io/file/csv-comments/

Use case

Easier debugging in CSV and TSV files by allowing directly commenting out lines in those files. This could also help to add some comments and explanation to those files without breaking them.

Suggested implementation

I think this should not be default behaviour of the function but adding an option like comments:true would be an ideal solution IMO

Thanks!

[bentsherman]

Related: #3632