2103 publish event on feedback nd

This change includes:
- IPC caching sequenceNodeKey and seqNodeIdentifier (in a structure called ItemSniRegistry)
- IPC having the role of firing the "activity-event"
- SubmitManager triggering the activity-event on feedback

@mlippert Could you please code review.

There is a server part of this which I will ask @seannives to review. 

The server side of this feature is in
https://github.com/lbondaryk/BrixServer/pull/64