baseldap: Handle missing parent objects properly in *-find commands
The find_entries function in ipaldap does not differentiate between
a LDAP search that returns error code 32 (No such object) and LDAP
search returning error code 0 (Success), but returning no results.
In both cases errors.NotFound is raised. In turn, LDAPSearch
commands interpret NotFound exception as no results.
To differentiate between the cases, a new error EmptyResult
was added, which inherits from NotFound to preserve the compatibility
with the new code.
This error is raised by ipaldap.find_entries in case it is performing
a search with and the target dn does not exist.
https://fedorahosted.org/freeipa/ticket/4659
Reviewed-By: Jan Cholasta <jcholast@redhat.com>