Make /authorize endpoint accept OIDC arguments

[niclaslindstedt]

When logging in with Blazor, this url gets called:

https://localhost:5011/oauth2/authorize?client_id=11111111-1111-1111-11111111111111111
  &redirect_uri=https%3A%2F%2Flocalhost%3A5012%2Fauthentication%2Flogin-callback
  &response_type=code
  &scope=openid%20profile
  &state=4189f1c5eb134962ab3998ae3e882abd
  &code_challenge=dJBLgGeU1VJt0R55orSTpYhkAl8IIMvSRnDBZrtPLuA
  &code_challenge_method=S256
  &prompt=none
  &response_mode=query

It returns 400 today. Make it work.