Scope out Oauth worked needed on backend

[chouinar]

Summary

Rough work needed:

• API endpoint that takes in information from Oauth2 (login.gov) id_token jwt
• Same endpoint creates a JWT we use internally in the API to connect requests to a user
• Setup of basic user tables
• Setup of a GET /user endpoint that uses this auth token

Acceptance criteria

• Scoped out and written tickets for work needed on backend API

[chouinar]

Rough backend tickets

Create DB tables

#2716

Create a stub endpoint for /users/token

Should return:

• token
• user object
• whether the user is new

#2673

Implement integration with Oauth's jwk endpoint to fetch public token for validation:

https://pyjwt.readthedocs.io/en/stable/usage.html#oidc-login-flow

#2721

Setup logic to create our own JWT

#2808

Connect everything together in /users/token

#2810

Setup JWT parsing for our own JWT

#2809

Setup a GET /user endpoint that uses this auth

Takes in JWT we created, connects it to a user

#2676

[chouinar]

[chouinar]

Went over this in refinement, I think our rough plan is scoped out and agreed upon