Add metadata groups to closure tables
Created by: wilsonmr
Without spending more time on this, this was the best I could do. There seems to be a fair amount of redundancy but I think there isn't a better way to do it without getting rid of backwards compat.
Example report: https://vp.nnpdf.science/6oHHKWGkSw-d-LxFX59Fig==
the groups are much smaller so there are bigger fluctuations. The worst one is probably jets which actually has a fair amount of data. Anyway people asked for it, so here it is.