Standard method for rolling up taxa ranks

[mihow]

Background: It would be more helpful if Antenna never shows low-confidence results (eg. "I am 0.01% certain this is a Spotted tussock moth"). Instead it's ideal if we keep rolling up to the next higher taxon rank until the confidence score is above a given threshold, until we can say "I am 60% certain this is in the family of Erebidae moths".

Find the method used in Fagner's evaluation code as a starting point.

If the calibrated softmax scores of a prediction are below a threshold, roll up all predictions for that image to the next taxon level, re-weight the scores and repeat until the top-1 prediction is above the threshold. Or use another method?

The inference API should return more in-depth data about each prediction.

Depends on #43