A notification should generate when an Instant Answer status is updated

[zekiel]

When an instant answer status is updated, a notification should be sent to everyone who follows that idea.

Followers = anyone who posted, commented, or voted on the idea.

E.g. When "Needs Developer" is updated to "In Development" https://duck.co/ideas/idea/841/english-etymology-instant-answer

[Getty]

We actually have an event for this, we just dont expose it yet as notification option, it needs a bit tune up so that you can actually see the change, this will go into a general system about "update" events (as we want the same technology for all updateable entries). I keep this task as reference for this change.