Name mangling of acronyms

The current algorithm for name mangling is(incorrectly?) considering subsequent uppercase characters as separate terms, e.g.:

externalID -> external_i_d as discovered here.

This is a pretty widely adopted pattern in the presence of acronyms. I understand that its an edge case but I think that we should improve the algorithm to handle those use-cases:

externalID -> external_id

the tricky part is in the presence of suffixes(although completely deterministic) where we should make sure this conversion is applied:

IDExternal -> id_external

another possible source of issues is single-character terms:

MeADeveloper -> me_a_developer

I hope I captured all of the invariants, let me know if I'm missing something 🙏