Provide hints in render_ticket_action_control

[ethan.jucovy@…]

WorkflowNotificationPlugin currently does nothing in render_ticket_action_control, since it doesn't itself provide any workflow actions.

However, it should return None, None, hints instead of None, None, None as it currently does.

The hints would inform the user about the email(s) that will be triggered. I'm thinking subject and recipients would be most appropriate, e.g.:

[Next status will be closed. The resolution will be set to _.] An email titled "Your ticket has been closed" will be sent to joe. An email titled "The ticket you are watching has been closed" will be sent to bob and nancy.

Not sure if we would be able to do this with 100% accuracy in case of .condition properties.

Nice-to-have: hover over a hint sentence to preview the full email that will be sent.

[ethan.jucovy@…]

Whoops - forgot to update this ticket ​when I implemented this feature.

There's a bug in the hints (they aren't condition-aware) reported in #11924.

And i have to make a new release containing this feature -- the last release, 0.5, was before this change was made.