New UI: Phosh

All Phosh packages are packaged. Right now rootston runs but the Phosh shell is missing gnome-settings-daemon so it fails at launch. gnome-settings-daemon however can't be installed due to it still being version 3.26, and other GNOME packages already being 3.28. This was the case for gnome-shell and gnome-session as well but I've updated those to 3.28 myself, and I made a PR to get gnome-shell 3.28 upstream.

However, gnome-settings-daemon 3.28 fails to compile due to some missing ITS rules. From a quick internet search it seems this is due to Alpine's polkit being outdated (0.105 while 0.115 is out). The newer version is dependent on mozjs52 which I have as of yet not managed to package, so it would be nice if someone else could take a look at this. It would be wise to take a look at Adélie Linux's packaging: mozjs and polkit.