Architectural goal of this update is to decouple users and questionnaires.
Note that first/last names are being moved to the user model too. This way admins do not need to have questionnaires, and can still be considered a full "user".
Implementation notes for self:
- Email fallback for full name when no questionnaire present is no longer needed
- Moved
first_name and last_name columns from questionnaire to user
- Moved
full_name method (?) to user