Implement Jetty HTTP/1.1 and HTTP/2 Client support for ROP Client

The goal is to add Jetty Client support for ROP client as a separate module with both HTTP/1.1 and HTTP/2 implementations.

The solution is implementing ROPConnector interface with Jetty's HttpClient for HTTP/1.1 and Jetty's HttpClient over Http2Client for HTTP/2 .

Depends on your needs, you could use HTTP/2 implementation with or without ALPN, which could be configured by Constants.ROP_SERVICE_USE_ALPN_PROPERTY.