Add operation handler to list all deployed webservice endpoints

To list all the deployed webservice endpoints:

[localhost:9999 /] /subsystem=webservices:list-endpoints
{
"outcome" => "success",
"result" =>

{ "deployed-count" => 1, "jboss.ws:context=TestService_web,endpoint=W2JTest" => [ ("address" => "http://localhost:8080/TestService_web/jaxws/W2JTest"), ("wsdlURL" => "http://localhost:8080/TestService_web/jaxws/W2JTest?wsdl"), ("shortName" => "W2JTest"), ("implClass" => "org.jboss.ws.W2JTestImpl") ] }

,
"compensating-operation" => undefined
}