This implementation is now a direct replacement for the `kernel32` one.
New bitflags for named pipes and other generic ones were added based on
browsing the ReactOS sources.

`UNICODE_STRING.Buffer` has also been changed to be nullable, as
this is what makes the implementation work.
This required some changes to places accesssing the buffer after a
`SUCCESS`ful return, most notably `QueryObjectName` which even referred
to it being nullable.