Add JSON logger in `log/api_json.log` for Grape API endpoints
We get JSON entries that look like:
{"time":"2017-09-07T14:47:24.127Z","severity":"INFO","duration":244.18,"db":0.0,"view":244.18,"status":"fail","method":"GET","path":"/api/v3/users","params":{},"host":"localhost","ip":"127.0.0.1","ua":"curl/7.43.0"}
Closes #36189 (closed)
Edited by Stan Hu