Ability to create registration forms

The platform currently lacks an important feature to allows organizers to create custom registration forms/questions for competitions and display them on the registration page. This functionality would be beneficial for tasks that share private data and require participants to provide certain information, such as email, full name, affiliation and address, to name a few, to build an "agreement" form. Based on the validity of this information, organizers could decide whether to accept or deny a participant's request to join a competition. The participants' responses could be stored and displayed in the "Participants" tab of a competition, possibly as a modal behind a button just before the accept/deny button, to avoid cluttering the interface. After reviewing the responses, organizers could then press the accept or deny button.

Using a "fact sheet" approach could eliminate the need for additional libraries. An additional tab in the administrative section of the competitions, or a new section in the "Participation" tab, could allow organizers to add new fields, similar to the fact sheet in the "Detail" tab, to define the competition registration questions. These entries would then be displayed on the registration page for participants to fill out, and the responses would be shown in the "Participation" tab for organizers to assess and make a decision.

Additionally, these responses should be visible and accessible only to organizers via API.

Start by tracing the competition registration page, the administrative Participation or Detail tabs, the Participants view, and the API mentioned in the issue. Done would include organizer-defined registration questions, participant responses shown to organizers for accept or deny decisions, and organizer-only API access.