pytest:sddl: tests around spaces in access flags and SIDs

pytest:sddl: tests around spaces in access flags and SIDs

It turns out that in accesss flags Windows will allow leading spaces
and spaces separating flags but not trailing spaces.

We choose to follow this in part because we found it happening in the
wild in our tests for upgradeprovision until a few commits ago.

Windows will also allow spaces in some parts of SIDs.

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