Implement system to manage status of non-hacker participants

[taesungh]

For a fully streamlined check-in process, we'll want to make sure our mentors, volunteers, sponsors, and judges have updated statuses during check-in. This will help ensure an arbitrary person who just signed the waiver isn't admitted to the event.

• Figure out how to store first and last names of non-hackers and input roles
• Add Roles for other non-hackers #331
• [API] Add Admin endpoint for directors to confirm attendance of a non-hacker #322
• [PMS] Include confirm attendance option for non-hackers #356
• [API] Allow checking in other types of participants #355
• [PMS] Non-Hacker Check In Fixes #371

[taesungh]

Considering complete as all tasks finished and event is over. For reference, names and roles of non-hackers were manually added to the database. For next year, we could consider a better self-service system for all directors (not just Tech) to manage non-hackers through the Admin site.