Add StatusSelector with popover
This replaces the status Combobox on the bottom side of the contact list. The Combobox had placement issues and often opened empty, forcing the user to scroll down in order to see the items. A popover does not have this issue.
I separated the MenuButton widget (including the Popover) from the roster to make it reusable in other places.
I didn’t reimplement the 'Free for Chat' show value yet. Should I?