Gene classification counts

I'd like a count of classification clinical significance on top of the gene grid

We already do this on the tag page - ie it shows "SomaticReportable: 3024" and if you click on the label, it filters the grid to those pathogenicities. James already has nice looking boxes of `[B]` or `[LB]` or `[P]` with colour scheme already

This is useful for working out the disease state of a gene etc

I googled for "clinvar gene" and [found this](https://clinvarminer.genetics.utah.edu/variants-by-gene/GATA2):

Might be good to also get aggregate counts for conditions in the gene like this.

Put behind a setting, decide in meeting whether it should be enabled in Shariant by default (or maybe we can try and decide based on testing)