s4: torture: SMB2. Add a new test that exposes interesting SD query behavior.

s4: torture: SMB2. Add a new test that exposes interesting SD query behavior.

If we open a file without READ_CONTROL, requesting a security
descriptor fails with ACCESS_DENIED if any of the requested
bits OWNER|GROUP|DACL are set.

However, if we send zero as the requested bits then a
security descriptor is returned containing no data,
even though reading an SD should fail based on the
access permissions we have on the handle.

This has been tested against Windows 10, and also
passes on Samba - although in smbd we actually
read the SD off disk first, before nulling out
all the data we read. We shouldn't (we have
no rights to do so) and a subsequent commit
will fix this.

This was discovered when investigating the
smb2.winattr test, which currently relies
on exactly this behavior. It shouldn't
and the next commit will fix that.

I wanted to preserve the current smb2.winattr
behavior in a test though.

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