astakos: Properly display user status

Fix AstakosUser.status_display so as not to miss some states. Include all
related flags in user-show and group them together.
astakos: Include display name in user listing

Include display name (email) in default output of user-list management
command. Remove flags 'verified' and 'moderated' from default output.

Keep --displayname for backwards compatibility.
astakos: Print UUID of newly created user