utils: extend some find_domain_* calls to search disabled domain
This extension is needed to support disabled domains since it is
now important to know if a domain is really unknown or only disabled.
While an unknown domain might typically lead to an error, a caller might
just ignore requests for disabled domains or objects from disabled
Related to https://pagure.io/SSSD/sssd/issue/4078
Reviewed-by: Pavel Březina <email@example.com>