More opinionated checks and warnings pushed to the anglerfish report

[remiolsen]

Currently anglerfish is taking a "just the facts" approach to reporting the results. It does not have any opinion for instance if it thinks your pool is unbalanced. Some warnings are buried in the log output, however. Maybe it should report checks (like FastQC does), along with metrics and their thresholds for each check. For instance

• Report the overall pool variability
• Report sample dropouts
• Report high number of unmatched and unknown indices
• Report lenient mode outcomes (flip, no flip, ambiguity)

Also the thresholds should be configurable.