Add X-Vcap-Request-Id to stderr logging output

[a18e]

• A short explanation of the proposed change:

  • X-Vcap-Request-Id is now included in stderr output to make correlation with access log entries easier

• An explanation of the use cases your change solves
  Easier analysis of websocket connection issues

• Instructions to functionally test the behavior change using operator interfaces (BOSH manifest, logs, curl, and metrics)

  1. cause an error that results in stdrerr output, e.g. by having an app time out
  2. observe logging

• Expected result after the change

stderr:

{"log_level":3,"timestamp":1652447228.7253733,"message":"websocket-forwardio","source":"gorouter.stdout.request-handler","data":{"RemoteAddr":"172.19.0.4:44124","Host":"js-ws.cf.local","Path":"/slow","X-Forwarded-For":["172.19.0.1"],"X-Forwarded-Proto":["https"],"X-Vcap-Request-Id":["3688e056-611f-49c8-7d16-3b1b2b2fbc0d"],"error":"timeout waiting for http response from backend"}}

• Current result before the change

stderr:

{"log_level":3,"timestamp":1652447458.127469,"message":"websocket-forwardio","source":"gorouter.stdout.request-handler","data":{"RemoteAddr":"172.19.0.4:44842","Host":"js-ws.cf.local","Path":"/slow","X-Forwarded-For":["172.19.0.1"],"X-Forwarded-Proto":["https"],"error":"timeout waiting for http response from backend"}}

• Links to any other associated PRs
  Improve Websocket Error Logging #317 - (original PR)

• I have viewed signed and have submitted the Contributor License Agreement

• I have made this pull request to the main branch

• I have run all the unit tests using scripts/run-unit-tests-in-docker from routing-release.

• (Optional) I have run Routing Acceptance Tests and Routing Smoke Tests on bosh lite

• (Optional) I have run CF Acceptance Tests on bosh lite