Cleanup and refactor course.controller.ts

[AdamFipke]

There's lots of stuff here, but some things I noticed:

• Many endpoints there are bloated and should be refactored into service functions
• checkMeIn, checkMeOut, setTaExtraStatus, createQueue could all be moved to queue.controller.ts (and queue.service.ts. Along with moving over tests and reorganizing api/index.ts)
  • Small thing: Some of these have isDisabled in their queue queries and will return 404 if the queue is disabled when it should probably return 400 "queue is disabled" instead.