Add queue cutoff line and queue join cooldown (resolves #29 and resolves #31)

[NicholasBottone]

Resolves #29 and resolves #31

Requires backend changes proposed in nthnluu/hours-backend#14

• modify the queue struct model to include a field representing the ticket ID of the last ticket before the cutoff (or null if the cutoff line is at the top / before any tickets)
• modify the cutoff request to take in a ticket ID for the position the cutoff point should be
• modify the backend endpoints to update new models
  • starting cutoff mode should set the queue's cutoff ticket to be the id of the last ticket in the queue
  • when a ticket is deleted, check if the ticket id matches the cutoff ticket - if this is the case, set the cutoff ticket to the ticket id of the ticket before this one (or null if this is the first ticket in the queue)
  • when the queue is shuffled, disable the cutoff line
  • when a ticket is marked as completed, do the same thing as when a ticket is deleted
• modify the frontend to send the position the cutoff point should be with the cutoff request
• display cutoff line on the frontend using the new information provided in the queue object

[vercel]

Someone is attempting to deploy a commit to a Personal Account owned by @nthnluu on Vercel.

@nthnluu first needs to authorize it.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated
hours-staging	✅ Ready (Inspect)	Visit Preview	Jun 17, 2022 at 6:34PM (UTC)

[n-young]

lgtm, it'd be nice to see screenshots though. i'll approve now, could someone send me screenshots via slack before merging? tks

[NicholasBottone]

@n-young @nthnluu @neilramaswamy I think I've resolved any issues, please review again and see if there is anything else that needs changing before release

[neilramaswamy]

Mostly style comments; I didn't actually run this but most of this looks like it'll work. I also expect that the time-limit will be enforced on the backend, correct?

[NicholasBottone]

Not sure why github isn't letting me request re-review, but addressed PR feedback again @nthnluu @neilramaswamy