macosx: Prevent selection of the outer cells in the audio group selection table view

At the moment the audio group selection table view (the one on the right) exhibits strange behaviour due to its nesting of views, where one can select the entire outer "album cell".

This PR changes this to disable row selection of the "super" cells in the audio group selection table view.

With current changes:

Screen_Recording_2022-08-04_at_02.12.31

Before the changes:

Screen_Recording_2022-08-04_at_02.13.42

Signed-off-by: Claudio Cambra claudio.cambra@gmail.com