Show Now Playing markers on all playable items, not just tracks

[confact]

I want to see which playlist is playing right now on the left sidebar, for easy navigating.

[jpochyla]

You can see which playlist is playing in the "now playing" section in the playback bar -- you can also navigate to it by clicking the section. I personally don't plan on working on this, as it seems a bit inconsistent with the rest of the UI. In case we would add NP markers to more UI items (artists for the top tracks, albums, etc.), we could add it to the sidebar as well.