Introduce Program Configuration (Set Live Phases / Banner Message)

[DallinFromEarth]

This PR lays the ground work for editable configuration settings for the Autograder.

Changes

• New Config Tab
  • this is the home for any editable settings we wish to have for the autograder
• Phase enabling and disabling
  • Admins may now enable and disable student submissions wholesale, or on a phase by phase basis
• Banner message
  • Admins may also set a Banner message, which will appear to all signed-in users at the top of the page
• Configuration Structure
  • Using @pawlh's Config Table in the database, active phases and banner message are stored in
  • All users can retrieve config info from /api/config with a GET request
  • Changes to the config are done via /api/admin/config with various POST requests
  • Any config info that students shouldn't have access to, but admins might new, can be retrieved via /api/admin/config with a GET request
• Queue Status tab has been relocated to the bottom of the submissions tab

Future work

Somethings that should be added, but I didn't have time. (I'm going out of town this next week)

• Canvas Integration (Canvas course id and assignment Ids should be editable from here)
• Penalty Percentages (Late and Git penalty should be editable from here)
• Hide disabled phases from the student drop down
• Any other magic number in the code should be moved to a config option #156
• Config info needs to be moved to a central location where all components can access it, like in a ConfigStore or something

I would be happy to tackle all of these, but if anyone wants to do it while I'm gone, feel free to. I'll be back in a week.

[DallinFromEarth]

Do you think there could be a way to display that a particular phase is disabled to the student and disable the submission button, rather than just relying on the backend to refuse them and send an alert?

Yes there is. That's why there's an endpoint for the student to get config info. I'll be implementing that when I get back