Add notification state to "final" published notification when publishing with descendants

[kjac]

Prerequisites

• I have added steps to test this contribution in the description below

If there's an existing issue for this PR then this fixes #14543

Description

This PR rolls back the functional breakage introduced by #14763 and fixes the original issue (#14543) in a non-breaking way.

Testing this PR

Create a notification handler that logs all "saving", "saved", "publishing" and "published" notifications for content.

Perform "save and publish" on an unpublished structure of content (including all unpublished descendants). Verify that:

1. The same amount of notifications are fired before and after applying this PR, and in the same order.
2. The "published" notification contains state from both the "saving" and the "publishing" notification of the root content being published.

[Migaroez]

Looks good!