Fix reversed logic for hold "blob" notes

Hold notes (at least at the data level) allow for both staff and
"private" notes to be attached. This code intended to show "private"
notes to the hold owner and staff notes to staff, but had the logic
reversed.

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Kyle Tomita <ktomita@catalystitservices.com>
Allow access to public hold notes via hold "blob"

If a hold note is marked as "public", it seems reasonable that it
should be visible to anyone who can see that hold, regardless of
who created the note.

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Kyle Tomita <ktomita@catalystitservices.com>