feature request: better separation of instrument labels

I think it would be good to e.g. have a pipe between various aliases. Otherwise it looks a bit like we have a "Trumpet Natural/Trumpet Slide" or a "Harmonica Tin/Sandwich"

No file, test, or entry point is named; start by locating the code that renders instrument labels and inspect how aliases are joined. Done means distinct aliases are visibly separated with a pipe, so examples such as “Trumpet Natural | Trumpet Slide” no longer read as one instrument.

Written by the indexing model from the issue text.