Limit label maximum width, to avoid breaking UI.
Change label to use plasma components 3, for theme color compatibility.
Use of implicit sizes, to avoid binding loops.

Note: Didn't make use fillWidth because we need the button area to be
only on the text, and not in the empty area.

Use applet outside of systemtray and limit it's width.
If device description is not long enough, enable in the configuration
"Add virtual output device for simultaneous output on all local sound cars".
Before: Hamburger menu moves to the right, and there is no eliding.
After: Proper display.

BUG: 417074
BUG: 417106