fix #2275

[dustinrue]

Description of the Change

Refactors the multi site handling so that when blogs are updated (marked as spam, archived or deleted), their indexes are also removed from the ES server. Also protects global indexes, like User, from being deleted.

Alternate Designs

Benefits

Keeps backend servers clean of unwanted data

Possible Drawbacks

It's possible for data meant to be kept to remove. Users should use ep_keep_index to keep the data.

Verification Process

Refactored the code then tested to ensure updated sites had their data removed. One think I'm seeing is that activating a site again does not cause it to be reindexed again.

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Applicable Issues

Resolved #2275

Changelog Entry

Fixed #2275 - ElasticPress will now remove data from Elasticsearch on a multisite network when a site is archived, deleted or marked as spam

[oscarssanchez]

The code looks good to me, the only thing I noticed when testing is if the site status changes to publish it won't attempt a reindex. Should we trigger this or add a notice for the specific site?