Security proxy logs are missing statuscode and response time

We did agree that it would be best to intercept logs at SP-level. However, it does not track those 2 metrics.

It should be possible to add some logic for that, at around this place https://github.com/georchestra/georchestra/blob/master/security-proxy/src/main/java/org/georchestra/security/Proxy.java#L676