[LYB-5] Epic: Authentication

[rtrox]

Authentication will happen via "AuthProviders", which are able to handle login events. Logging in should create a JWT, and a middleware should handle populating the User object & their claims to the context from the JWT.

Example here:
https://github.com/rtrox/spotify-sentry/tree/main/internal/auth

auth middleware, though, should end up in the middleware package.

_{From SyncLinear.com | LYB-5}