Description of problem:

"sssctl user-checks" also query the IFP interface of sssd. The problem is, that
this command only displays POSIX user attrs, no matter if we configured the
InfoPipe for additional user attributes.

for example, if I have the following configuration snippet:
[ifp]
        debug_level = 9
        allowed_uids = ondrejv, root
        user_attributes = +mail, +telephoneNumber, +givenname, +sn

I would expect the "sssctl user-checks" command will
- also return the value of "mail, telephoneNumber, givenname, sn" attributes
- ideally, we could make the "sssctl user-checks" also available for non-root
users (ondrejv in the example above), but I guess I am asking too much :-)

I know I could get the results with dbus-send or the Python dbus module, but
parsing the output of sssctl is better parseable for a simple bash script.