ZTS: Add tests for DOS mode attributes

Create a new section of tests to run with acltype=off.

For now the only test we have is for the DOS mode READONLY attribute on
FreeBSD.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11734