Traefik OIDC middleware

WIP warning! This middleware is under active development.

This middleware is supposed to replace the need for the forward-auth and oauth2-proxy when using traefik as a reverse proxy.

Configuration options

testData:
  providerURL: https://accounts.google.com
  clientID: 1234567890.apps.googleusercontent.com
  clientSecret: secret
  callbackURL: /oauth2/callback
  scopes:
    - openid
    - email
    - profile
  sessionEncryptionKey: potato-secret