NSS: add *_EX version of some requests
To be able to send the flags to the SSSD responder new request types
with an _EX postfix are added which expect and additional 32bit flag
field after the name or the id of the requested object.
Related to https://pagure.io/SSSD/sssd/issue/2478
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>