feat: handle user deletion event on the network

[adekbadek]

All Submissions:

• Have you followed the Newspack Contributing guideline?
• Does your code follow the WordPress' coding standards and VIP Go coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Adds user deletion handling.

(Note: this is a part of integrating the changes from the data-integrity-improvements branch (#89))

How to test the changes in this Pull Request:

1. Register a user on one of the sites, wait for the data to sync*
2. Delete the user on one of the sites, wait for the data to sync
3. Observe the user was deleted from all sites
4. Observe there is only one network_user_deleted event in the event log

* can be sped up by running wp newspack-network process-webhooks on the node and then wp newspack-network sync-all on the other node sites

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully ran tests with your changes locally?

[chickenn00dle]

Hey @adekbadek,

I'm running into issues testing this one. A couple things:

1. When I delete the propagated user from a node, I see the delete event, but the user is never deleted from the hub site. Here is what I see on the node:
   

And once the event propagates, this is what I see on the hub:

But the user is never deleted on the hub:

2. Might be related to the above, but when a user is deleted, I am also seeing the user updated event trigger (pictured in the screenshots above). I would expect this event not to be needed once a user is deleted. I wonder if this also has something to do with why the user persists on the hub even after the deletion event is processed?

[adekbadek]

1. The code was handling only deletion of Network Readers, so if a reader deleted their account on a non-origin site, the account would not be deleted elsewhere. This was erroneous, fixed in 998b4fd
2. Fixed the superfluous network_user_updated event triggering by deletion in 1d6ff1c

[chickenn00dle]

Nice! This is working as expected now. I noticed some strangeness with the logs, but considering the primary functionality is working and deletions are ultimately being logged, I'm gonna go ahead and approve this.

[chickenn00dle]

Just noting this results in conflicting messaging in the logs where the account is logged as skipped, but then is logged as deleted:

[25-Apr-2024 14:07:47 UTC] [3110] /Users/raz/Sites/newspack/network/includes/class-data-listeners.php:103 User deletion with email: raz+networksubscriber3@automattic.com was skipped due to filter use.
[25-Apr-2024 14:07:47 UTC] [3110] /Users/raz/Sites/newspack/network/includes/incoming-events/class-user-deleted.php:70 User raz+networksubscriber3@automattic.com deleted.

Since the final log indicates the deletion was successful, I think this is not a blocker.

[matticbot]

🎉 This PR is included in version 1.7.0-alpha.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀

[matticbot]

🎉 This PR is included in version 1.7.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀