Populate the username in the cache automatically when the corresponding session is not in the cache. (for logbook routes at least)

IT can happen that the frontend sends a valid session, but this session is not in icat+ cache because

• icat+ restarted
• the icat+ instance which is targeted does not have the information about the corresponding session yet (ie the previous login step was done on another instance)

When such a request arrives, we want icat+ to automatically updates its cache adding relevant missing information in its cache