samdb/cracknames: support user and service principal as desired format

samdb/cracknames: support user and service principal as desired format

This adds support for DRSUAPI_DS_NAME_FORMAT_USER_PRINCIPAL and
DRSUAPI_DS_NAME_FORMAT_SERVICE_PRINCIPAL as desired formats.

This also causes the test in cracknames.py to no longer fail.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12842

Signed-off-by: Bob Campbell <bobcampbell@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Mon Jul 24 11:10:26 CEST 2017 on sn-devel-144