Track which editor took which step on submission

[aguywithanidea]

As a prequel to grouping submission by editor, need to capture which editor takes which steps on the submission.

• add a link from the top of this page to the bottom, where a submission management "history" will be displayed, including the action taken, the datetime, and the editor. Will require editor WP ID to be stored with the submission history (this screen) so we can pull it back in later.

If editor has a HP ID, we should push that to HP as well, so we can tie together.

[aguywithanidea]

State transition definition:

• if current state = 'read' track it regardless of editor (via exception to state transition)
• else, only track the state transition of the editor who initiated the transition. (via state transition)

[aguywithanidea]

code updated and tested against server code which has been pushed to prod

[aguywithanidea]

Deployed as part of 2.6.0