NOTE: This ticket is blocked by the creation of the schema
As an event organizer, I want the invitation list to be stored, so that it can be generated upon my request and so that I can refer to it in the future.
Background: This ticket focuses on the actual storage of the invitation list in the database. The UI of the organizer inputting the information to generate the invitation list is handled by T356679, while the UI for handling the invitation list results is handled by T364804. The pending state after the request has been issued will be handled in T364802. The work to refactor the invitation list (T365628) and to store + generate upon organizer request (T366641) will also be handled separately.
Acceptance Criteria:
- Implement the storage logic, so that we can store invitation lists in the DB