Add "deep dive" feature to help users identify likely root cause

[lukasvermeer]

I've been reluctant to let go of identifying problematic variants for too long. @geoprofi has convinced me. We should just check for SRM overall (see #16).

However, in addition, we could still try to provide an "auto deep dive" feature which tries to find likely causes (we could base it on the taxonomy maybe), but that would be a different thing from the simple check functionality.