mpdmenu: Use MBIDs for albums instead of name matching.

mpdmenu: Use MBIDs for albums instead of name matching.

This enables much more accurate album menus, e.g., fully distinguishing
between multiple versions of the same release that would previously be
merged together into a single display.

This also adjusts the album menu to use modern MPD database query
features, so we can correctly display all tracks from the album
regardless of the state of the play queue.