<fb-library-tree> row double-clicked — request play / queue.
<fb-library-tree>
Optional
Opaque identity used when display names cannot identify the album.
The row's data-artist, as in FbLibrarySelectDetail.artist.
data-artist
Exact members of an artist's album row; pass them to addToPlaylist.
addToPlaylist
<fb-library-tree>row double-clicked — request play / queue.