lockscreen: Use more vertical space for notifications
Was looking at somehting else but the lock screen (one of phosh's earlier widgets) needed some fixup first making it work better with many notifications open:
- fix inconsistencies regarding clock size between media player widget and notifications
- use more vertical space for notifications
- dont cut off notifications below the media widget but move both into the same scrolled window
- use a revealer for the media player too making it more appealing when it's show / hidden (and consistent with notifications)
Closes: #593 (closed)