selftest: Add test for a re-animated object conflict

selftest: Add test for a re-animated object conflict

Added a test to simulate a user accidentally being deleted and 2
different admins trying to resolve the problem simultaneously - one by
re-animating the object and one by just creating a new object with
the same name.

Currently this test fails on Samba because it chooses the higher
version
number as the winner instead of the latest change.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13039

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>