libbsm: honour AU_OFLAG_NORESOLVE
AU_OFLAG_NORESOLVE is documented as "Leave user and group IDs in their
numeric form" but it was not actually tested.
OpenBSM pull request at https://github.com/openbsm/openbsm/pull/85
PR: 282271
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D47263