Add a display of previous and next track in the top bar. It should show the cover, title and album name. On click, the player should switch to it.
The groundwork has now been done. On the c++ side, the manageheaderbar must be connected to the previousTrack and nextTrack signals of the mediaplaylist.
The information must be made available to qml similar to the currentTrack properties.
On the qml side, the HeaderBar must listen to the added properties and display them.