feat: clean notifications

[alfetopito]

Summary

• Add a cronjob to clean notifications whose notification-template dueDate is paste > 1 week
• Add a lifecycle hook to delete notifications when a notification-template is removed

Testing

1. Start the service locally
2. Add a few notification-templates, where:
   1. at least one is due > 1 week
   2. one is due < 1 week
   3. one is not due
   4. one doesn't have a dueDate
3. Add a notification for each notification-template
4. Add a notification without a notification-template
5. Change the conjob to run every minute (*/1 * * * * ) and start the dev server

• After ~1 min, the notification due > 1 week AND the one without notification-template should have been removed

5. Manually remove any notification-template using the admin panel

• The associated notification should be removed as well

[alfetopito]

Generated files after a yarn build.

Changes not related to this PR

[cowdan]

Just a couple of minor comments, otherwise lgtm

[anxolin]

Awesome, this is a neat solution!

I didn't know there was a cron in strapi, I thought you were adding it in GH. This is way better, and more secure so we don't need to give GH actions deletion access/

Thanks for fixing this