Exploded trees extension: hide deepest nodes / branches for approachability

[sidneymbell]

Context
One of the things that makes trees really intimidating to non-phylogeneticists is all the really deep branches / nodes. While these deep divergence events are super helpful for us as researchers, they can make the data more intimidating and unfamiliar to our counterparts in public health.

Description
0. Define parameter for each node along the lines of

1. Add a slider for user input to control how deep / shallow to make this cut

2. Ulta-bonus points: draw each resultant subtree as an unrooted tree, which then reconsitutes a "cluster diagram" like Epis are used to looking at, but with actual phylogenetic structure

Examples

Possible solution
Once exploded trees land with the next release, I'd love to give this a try myself. First implementing via a JSON with "filtered out" nodes marked with no valid color option so they aren't drawn, and then potentially actually trying out an implementation in the code base if the first exploration is promising.