Note API - Fix joining to and updating Notes

Note API - Fix joining to and updating Notes

Multiple bugfixes:

1. Could not join to Notes from APIv4 because it would "helpfully" insert a contact_id clause in the join
2. Creating a note with no contact_id was defaulting to the contact the note was about rather than the logged-in user
3. Updating a note was clobbering the contact_id and the privacy fields
4. Note ACLs were being applied incorrectly to the Note.contact_id field