Auth tests for end to end token generation

Make sure the agent claim is present

Make sure the agent claim in the right one

Make sure the agent claim value makes sense

If important, validate these keys as well

```json
{
"iss": "https://cubap.auth0.com/",
"sub": "auth0|62447bf424dc10011341226b",
"aud": [
"http://rerum.io/api",
"https://cubap.auth0.com/userinfo"
],
"iat": 1648655359,
"exp": 1680212959,
"azp": "62Jsa9MxHuqhRbO20gTHs9KpKr7Ue7sl",
"scope": "openid email offline_access"
}
```

This way, if either of us change something on Auth0 and break it, it will be detected on the next test.