Double user name shown when creating annotation

Username name can be persisted in the annotation model instead of the display name. Then sometimes we can have both and are differentiated by ARender.

Solution :
Arender Side:
Make the object UserContext customizable in the connector.
This object is used by ARender to retrieve any information about a User.
Connector Side:
Implements the new interface UserContextProvider and build the UserContext with direct the display name.

After that, only display name is showed while and after creating annotations