Interrogate the visiting scientist database

As a user I would like the experiment users to be populated as accurately as possible when I enter my RB number. Currently we populate the user list based on which users are associated with the RB number in the proposal database. There is also a visiting scientists database that has information on who is actually on site, we should interrogate this for information as well.

## Acceptance Criteria
1. There is a service that pulls information form the BusApps visiting scientist interface and stores it on instrument machines
1. When an RB number is selected the users are populated from this database as well as the proposals database