tweak: add new action hooks and deprecated existing

[ravinderk]

Description of the Change

As discussed, I deprecated dt_push_post and added two action hooks, dt_push_external_post and dt_push_network_post.

Closes #123

How to test the Change

• A notice should log in debug.log when use dt_push_post action hook
• dt_push_external_post and dt_push_network_post action hooks should not cause any issue when use

Changelog Entry

Added - dt_push_external_post and dt_push_network_post action hooks.
Deprecated - dt_push_post action hook

Credits

Props @dkotter @peterwilsoncc @dhanendran

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[ravinderk]

While checking existing action/filters hooks, I notice the following things:

• We only document one filter/action hook. As a developer, I notice the following issues:

  • I saw that in a few hooks, we pass class objects, meaning object types often differ, which can cause a fatal error. We should mention it in the hooks doc.

  • We show only one location of the filter doc. I think if we reuse the same filter at multiple locations and then mention this, it will be helpful for the developer

    List of a few hooks:

    • dt_push_post_args
    • dt_pull_post_terms
• We should mention multiple value types in the filter doc's return type. I noticed that dt_remote_get filter hook returns WP_Post , array, and boolean

Let me know if you want me to take action on the same pull request.

cc: @peterwilsoncc @dkotter

[peterwilsoncc]

A few minor notes inline.

[ravinderk]

@peterwilsoncc I merged your suggestion and replied to your question. This pull request is ready to review.

[peterwilsoncc]

Thanks, let's figure out the other hooks you mentioned on a follow up PR.