Taxonomic tree features

[JWCook]

I previously added an experimental LifeList.tree() method to render a life list (example on iNat) as a tree on the terminal.

This would be useful in some new features in Dronefly, so it would be worth cleaning this up a bit by separating the logic from display format.

Options

Options include:

1. rich.Tree subclass with .taxon attribute (with some additions I mentioned in PR comments)
2. pyinat.Taxon tree
   • Root node would be a Taxon object, with children recursively added using the existing .children attribute
   • Add a separate function to convert it to a rich.Tree for console display (which would work for any arbitrary taxon with children)
3. Hybrid class that inherits from both Taxon and Tree

Currently leaning toward option 2.

Other features

It would also be useful to allow making a tree from any collection of Taxon objects as long as there is exactly one root taxon.
Should this be determined by either id == 48460, or parent_id isn't in the list of taxa?

Related

Note: this is suitable for the size of, say, a typical user's life list (hundreds to maybe tens of thousands of taxa for power users), but it probably wouldn't perform well enough for datasets significantly larger than that.

For navigating the entire iNat taxonomy tree (~1.2 million taxa), there is this module, which uses pandas and multiprocessing: https://pyinaturalist-convert.readthedocs.io/en/stable/modules/taxonomy.html
Any similar features that need better performance could be done there.