macosx: Select artists view when clicking on music sidebar entry

This MR fixes some previously confusing behaviour regarding the "Music" section of the sidebar, which was previously selectable.

There is no real "music" section, but we still want to be able to click on "Music" and present it as a normal entry rather than having to create a detached section for its subsegments (which would look weird). With this MR it is clickable but doing so expands the music section and selects the artists view, which feels more natural

After changes:

Screen_Recording_2024-03-08_at_19.54.50

Before changes:

Screen_Recording_2024-03-08_at_20.15.11

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