pairtools - multiqc enhancements

[WardDeb]

• Custom multiqc module can be dropped
• Figure out a way to make bins consistent (if this makes sense) to avoid dist categories not being plotted:
  cfr.
  https://github.com/MultiQC/MultiQC/blob/ee1f63e5660e237f8056a284156553ad4b6df8f8/multiqc/modules/pairtools/pairtools.py#L179C1-L185C73