Raise an event on new enrichment data

From the return data, allow configuration to override a property value.

NOT FOR PRODUCTION (SPECIALLY NOT ON INTRANET !!!), ONLY FOR DEMOS.

Special case :

Custom model, returns a dc:nature value, given as image . this was trained from the intranet dataset.
Replace the nuxeo vision functionality of storing tags from the enrichment facet .

• Create an event when new enrichment data is available
• Create a default listener (configurable) to save the enrichment data to a property