macosx: Tweak general fonts, sizings, and alignments in library window

This MR removes a lot of custom fonts in favour of using default system fonts. This helps reduce the feeling of clutter and chaos in the UI by cutting down on the number of unnecessarily bolded elements, unevenly sized text, as well as unnecessarily oversized text, in favour of only bolding and enlarging text that is bolded or enlarged for a functional or structural purpose (e.g. current playing item, section header, etc.)

A few additional changes include some small tweaks to XIBs to improve text alignment and sizing

After changes:

Screen_Recording_2023-05-06_at_22.40.36

Before changes:

Screen_Recording_2023-05-06_at_22.45.30

Signed-off-by: Claudio Cambra developer@claudiocambra.com