[RFE] Add API to query "username" pattern
Some OSes have different rules for characters accepted for usernames. This way clients could be feeding express-installs with invalid usernames.
This was reported against Boxes in https://gitlab.gnome.org/GNOME/gnome-boxes/issues/31
And an implementation has been proposed in https://www.redhat.com/archives/libosinfo/2015-August/msg00001.html but that hasn't been accepted/merged.