Port to KStatusNotifierItem
Using SNI instead of QSystemTrayIcon allows to pass icon names and pixmaps for the main icon and overlay in combination. Make use of that functionality to support themes better.
This is a straightforward port with basically no more changes than necessary.
Unfortunately the overlay is a bit too small, but still recognizable:
Draft because I still need to test some of the edge cases.
Edited by Fabian Vogt