[applet] Simplify printer list item subtitle
The subtitle currently builds up a complicated string that tells you the number of active and/or inactive jobs. However what you really care about is the current state: idle or printing, paused, stuck, etc. I don't think The number of jobs is useful or actionable information. So let's remove it.
This happens to fix a bug whereby the state is displayed incorrectly.
BUG: 425534 FIXED-IN: 20.12.0
cc @teams/vdg