s4: torture: Add a new test - samba3.smb2.durable-open.stat-open.

s4: torture: Add a new test - samba3.smb2.durable-open.stat-open.

Passes against Windows. Shows that Windows allows a durable handle
on a leased open for READ_ATTRUBUTES only (a stat open).

Mark as knownfail for now.

NB. Not sure why we are testing smb2.durable-open against ad_dc
as that provisioning has "smb2 leases = no" which precludes
granting durable handles. Not changing for this bug but this
should be looked at in future.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15042

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>