Add granular settings for requiring staff initials for notes

Add granular settings for requiring staff initials for notes

Up till now, there has only been one setting for making staff initials required
for all of the various note fields. Instead, let's break this up into separate
org unit settings for each type of note field, giving us more flexiblity in
making use of the append staff initials feature.

These three types of notes will now have settings to add initials for each:

- patron penalties/messages
- patron information notes
- copy (item) notes

Signed-off-by: Ben Shum <bshum@biblio.org>