(whishlist) Add an option in the start/stop button on top to suspend.

I have been using mobian in my pinephone for a while and a feature that I would like to add is an option to explicitly suspend the phone. The start/stop button shown on the top bar of phosh already has "Lock screen", "Reboot" and "Shutdown" (maybe with other names since I am translating from my localization). I would like to see there a "Suspend" option. It is useful in cases in which I realize the battery is really low (below 5%) and I want to suspend immediately without having to wait for the automatic suspension to kick in.

Thank you for improving this amazing project!