Unify log messages style for all messages

[mrodm]

Currently, logs from the server itself are not formatted as a JSON as the other applications logs as noticed by @jsoriano in #1103

For instance:

{"log.level":"info","@timestamp":"2023-10-25T17:43:33.554Z","log.logger":"http","message":"HEAD / HTTP/2.0","source.address":"172.17.0.1","http.request.method":"HEAD","url.path":"/","url.domain":"localhost","http.response.code":200,"http.response.body.bytes":72,"event.duration":29288,"source.ip":"172.17.0.1","user_agent.original":"curl/7.81.0","url.port":8080,"ecs.version":"1.6.0"}
2023/10/25 17:43:39 http: TLS handshake error from 172.17.0.1:53032: remote error: tls: protocol version not supported
2023/10/25 17:43:43 http: TLS handshake error from 172.17.0.1:37008: remote error: tls: protocol version not supported

It would be great that all logs were formatted using the same logger if possible.