power-menu: screenshots: Allow to select area and timeout
While screenshoting the whole area on mobile is a good default allowing to set a delay and the area would be nice when the screenshot is toggled via the screenshot button in the power menu. We already allow for that when the screenshot is triggered via DBus.
This would also fix #943
(discussed before but never made it into an issue)
We can then also wire up the keybinding (default: printscreen) for this.
Edited by Guido Günther