Event on duplicate

As a application configurator 

I want to have a event fired when a document is created/modified and has duplicates
So that I can create a listener to manage them.

Add registry to event so it can be used in Studio.

Sequence:

• The indexation of the document is done via the dedup listener previously done
• We can try to check if the document has already some similar documents and fire this custom event at that time
  OR
• We can run another async listener to check those similar documents and fire the custom event