Strand bias (QC metric) in REViewer

[mdanzi]

Hi Egor,

I have a request for a new QC metric that would be analogous to the 'Fisher Strand' metric in GATK (https://gatk.broadinstitute.org/hc/en-us/articles/360040096152-FisherStrand). Basically, one would expect an even ratio of forward and reverse reads to be assigned to each of the two alleles at an STR site, but if there is a bias toward one of those directionalities on one of the alleles, it could indicate a low quality call.

Thanks again for all the great work you are doing on these tools!

Best,
Matt