ENH: Indicate reversions to root in branch tooltip, maybe even color reverted branches red and fat

[corneliusroemer]

The Usher tree continues to have huge issues with reversions. These are difficult to spot in Taxonium at the moment - unless you do a search for them.

It would be nice if reversions could be indicated if you hover over a branch, in the tooltip.

In addition, maybe reversions can appear as colored branches - or maybe as branch annotatations - which don't seem to be a thing yet other than for Pango lineages?