macosx: Fix playlist items originating from playing items in the browse view not having thumbnails
This PR fixes bugs with playlist table cell views. It also remove the VLCPlaylistImageCache, which is essentially a copy of VLCLibraryImageCache.
Before fix:
Screen_Recording_2023-02-04_at_02.51.50
After fix:
Screen_Recording_2023-02-04_at_02.57.34
Signed-off-by: Claudio Cambra developer@claudiocambra.com