IPA: Change ipa_server_trust_add_send request to be reusable from ID code
Expose a request ipa_server_trusted_dom_setup_send that sets up a
trusted domain. The setup might include actions like retrieving a keytab
for one-way trusts.
Creating the AD ID context for the trused domain is now done in the
caller of this new request.
Reviewed-by: Sumit Bose <email@example.com>