Use Jetty for communication from Worker to Server

Try using Jetty for communication between Server and worker as a POC. Create a separate branch and run tests. Use one of the ports from the port range dedicated to workers.

Using bundled Jetty like for HTTPS contexts in Data Services might bring these benefits:

• server.http.url property would not be necessary
  • we could choose the port and the context, so the address passed to the worker would be http://127.0.0.1:port/context
• it would give us more control over the configuration of the endpoint (timeouts)
  • currently, the timeouts are configured in the application container and we can't modify them