add max depth for `vskit expand`

[turbomam]

maybe I don't want permissible values created for all of the very specific sub-classes that are eligible in the dynamic enum definition

[cmungall]

Depth is a problematic metric here

• there are different ways to calculate it. When there are multiple paths is depth the max depth, the min depth, the average? is this over is-a, all edges?
• depth/level is often a very poor proxy for specificity. See the GO FAQ entry on this https://geneontology.org/docs/faq/#ontology

Exceptions are fixed level systems like EC.

If we add filters for depth, what about other derived statistics like information content?

I think a better methodology would be to use other OAK tools to explore the ontology to help manually curate shorelines that can be curated directly into ontologies, e.g using subsets or metaclasses.

[turbomam]

OK I'm convinced