PIMS Internal Notification Queueing

[dbarkowsky]

🎯 Summary

Purpose and Changes

Some code changes that help separate PIMS' reliance on CHES for queueing emails.
Because CHES has historically dropped emails that were queued for long periods of time and PIMS needs to queue emails potentially 90 days in advance, there have been issues with lost/unsent notifications.

The proposal in this PR is to instead place the burden of sending delayed emails on the PIMS backend instead.
Notifications are only sent to CHES on the date that matches their send date.
Additional cron jobs are necessary to monitor the status of notifications and send outstanding ones.

TODO

• Revise tests to match new code
• Add comments for documentation

🔰 Checklist

• I have read and agree with the following checklist and am following the guidelines in our Code of Conduct document.

• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation where required.
• I have tested my changes to the best of my ability.
• My changes generate no new warnings.

[github-actions]

🚀 Deployment Information

The Express API Image has been built with the tag: 3059. Please make sure to utilize this specific tag when promoting these changes to the TEST and PROD environments during the API deployment. For more updates please monitor Image Tags Page on Wiki.