[WIP] add participant auth endpoint and group tokens endpoints
Add stateless endpoints for
School Admin Portal:
- Get Group Tokens (School admin)
LimeSurvey Client:
- Participant authentication (student / mentor)
- Get Group members by group token
Refactor Model:
- Person -> Participant
- PersonGroup -> ParticipantGroup
- etc..
Edited by Hal, J. van (John)