[System Tray] Emit pressed signal on compact representation in popup, too
Some actions, such as middle click to mute, trigger only on press. Some applets also need a pressed-click because of some legacy autoclose on focus change bug.
Unfortunately, QML does not disambiguate the "pressed" property and "pressed(mouse)" signal with argument, so this has to be done awkwardly through QMetaObject on C++ side.
BUG: 426646 BUG: 452893 FIXED-IN: 5.25.0
- Middle click to toggle mute now works from popup
- Opening notification applet from history now works
- Didn't notice any other issues, could use some more real-world testing