Add a heart icon that displays whether a track is favorited (added to "Liked Tracks" playlist)

Is there an existing issue for this?

• [X] I have searched the existing issues

Pain

When checking out any playlist, the absence of an indicator of whether or not a track is liked is pretty annoying; I checked out spotube to see if it maybe had it, since Spotify removed it ages ago and it got getting more annoying as my library grew and time went by, since I don't remember every single song I liked :)

Suggested solution

Add a heart indicator :) Attached is a UI sketch of what this could theoretically look like. The hearts in the accent color indicate that a track is liked; the grey heart indicates that the currently hovered track isn't liked.

Useful resources

No response

Additional information

No response

Self grab

• [X] I'm ready to work on this issue! (I really like how spotube looks like, how it uses the accent colors and the fact that it's in Flutter; I'm a big believer in Flutter for desktop and would love to work on and use more desktop apps that are built in Flutter)

It's fine by me to also make this a setting, in case you'd prefer that; we can leave it turned off by default, too, but I'd rather enable it for everyone, since I believe it is pretty useful