NMS-10313 : Be able to use Proxy for any Monitor or Collector that uses HttpClient via UrlFactory (#2115)
* NMS-10313: Be able to use Proxy for any Monitor or Collector that uses HttpClient via UrlFactory
NMS-10312: Be able to use Proxy for any Monitor or Collector that uses HttpClientWrapper directly (#2114)
* NMS-10312: add HttpClientWrapperConfigHelper and apply it to Poller and Monitors
* NMS-10312: revert changes to poller-configuration.xml => remove "use-system-proxy" parameter