Fix admin search controller after changes to result format
Fix admin search controller after changes to result format

# The #979 admin user tweaks API changes altered the user ID in the results
# from _id to just id. These fixes were missed in
# 83becbbac462994b476e773113e4a19d9d616aff

ucam-cl-dtg/isaac-app,ucam-cl-dtg/isaac-app,ucam-cl-dtg/isaac-app,ucam-cl-dtg/isaac-app