Send patron notices via email for user initiated loan events, such as check in/out (i.e., check in or out receipt)

2019 03 15 - Splitting this into several separate features:
Send patron notices for user initiated loan events, such as check in/out (i.e., check in receipt and check out receipt) via email
Send patron notices for user initiated request events, such as recall request, page request, hold request. cancel, etc. (i.e., recall notice) via email
Send patron notices for time based loan events, such as due date/time (i.e., courtesy notices and overdue notices) via email
Send patron notices for time based request events, such as hold expiration or request expiration (i.e., hold expiration notice) via email
Send patron notices for user initiated fee/fine events, such as a new manual charge or payment (i.e., fee/fine receipt or new charge notice) via email
Send patron notices for item status changes (request related), such as available - awaiting pickup (i.e., available notice for recalled item) via email

Earlier:
This feature covers the work needed to make the patron notice policies effective. This is being split out of UXPROD-676 which was originally intended to cover Patron notice CRUD and making patron notice effective, but only CRUD is now expected for Q4.

This feature includes the scheduling functionality required to trigger time-based events/notices.