CACHE_REQ: Add a private request cache_req_locate_domain()
Adds a new request cache_req_locate_domain_send/recv. This request, if the
plugin that is being processed supports the locator, will call the plugin's
dp_get_domain_send_fn(). On any error, the request returns just the error
code. On success, the request returns the domain the object was found at.
If the getAccountDomain() method returns that the back end does not support
the locator method, all further getAccountDomain() calls are disabled for
that domain.
Related:
https://pagure.io/SSSD/sssd/issue/3468
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
Reviewed-by: Sumit Bose <sbose@redhat.com>