users: set profile full name when migrating #402
Description
The comments timeline displays full name, and defaults to username
https://github.com/inveniosoftware/invenio-requests/blob/b86dac0a7186ecf9edc8a3205f68dee567d9bc34/invenio_requests/assets/semantic-ui/js/invenio_requests/timelineEvents/TimelineCommentEvent.js#L141
Populate the full name properly.
