Access logging to standard out

[mlbiam]

Currently the proxy supports audit logs in the same way that the API server does. this is duplicative and doesn't cover a major use case of tracking which user is accessing each URL. From a SIEM perspective, it would be good to support a simpler logging model as well that logs:

1. timestamp
2. URL
3. User
4. Authentication success or failure (ie did the token fail)

this can additionally log other events too such as inbound impersonation

[mlbiam]

need to stop double logging the source ip