Option to create (strand-specific) coverage bigwigs

[SamBryce-Smith]

Following on from this week's concerns, it could be a good idea to have the option to generate plus & minus bigwigs for each BAM file, so can visualise strand-specific coverage over regions.

I can't see too many benefits on the splicing side, but for APA this could be particularly handy. Especially for regions where there are overlapping genes on opposite strands, it's not always super clear from the IGV BAM coverage profile whether it comes from one gene or the other.

Bigwigs are supposed to be smaller than BAMs, so could make IGV browsing more lightweight too...

Deeptools seems like a good suite to use for this, but will look into it on the side. If we do end up implementing this should definitely be optional

[SamBryce-Smith]

The conda env env/align.yaml has deeptools installed but haven't done anything with it. Hooking up should be straightforward (even with multiqc, some of their QC modules look handy)