Issue 51113 - Allow using uid for replication manager entry
Bug Description: Currently it was hardcoded to only allow "cn" as
the rdn attribute for the replication manager entry.
Fix description: Allow setting the rdn attribute of the replication
manager DS ldap object, and include the schema that
allows "uid".
relates: https://pagure.io/389-ds-base/issue/51113
Reviewed by: spichugi & firstyear(Thanks!!)