TUN-4655: ingress.StreamBasedProxy.EstablishConnection takes dest input

This change extracts the need for EstablishConnection to know about a
request's entire context. It also removes the concern of populating the
http.Response from EstablishConnection's responsibilities.

ingress/rule_test.go

@@ -14,7 +14,7 @@ func Test_rule_matches(t *testing.T) {
 	type fields struct {
 		Hostname string
 		Path     *regexp.Regexp
-		Service  originService
+		Service  OriginService
 	}
 	type args struct {
 		requestURL *url.URL