[Desktop][Playlists] Return the dates for songs added/playlists created

[moth1]

Previously, the desktop version of Spotify had the dates for when songs were added to playlists visible. This feature was useful both in tracking when my playlists were created as well as seeing when playlists created by others were last updated. Personally, I like being able to look back on my past music taste in ways beyond the once-a-year wrapup playlists, and likewise, I like being able to quickly see that playlists I am following have been updated. Returning the date added to the display besides the song length or name would be helpful and add to the spotify experience.