Added a Note Credential Type for Passphrase

Summary: Closes T8481.

Test Plan: Verify that in Passphrase > Create an option to create a Note credential exists and credentials of type Note are createable.

Reviewers: epriestley, #blessed_reviewers, eadler, lpriestley

Reviewed By: eadler

Subscribers: joshuaspence, epriestley, Korvin

Maniphest Tasks: T8481

Differential Revision: https://secure.phabricator.com/D13261