[IOT-1604] Fix cloud routing code

[IOT-1604] Fix cloud routing code

- Fix on do GET request to discovered resource server.
- changed DiResource to RouteResource
- code clean up

https://jira.iotivity.org/browse/IOT-1604

Change-Id: If1ccc98bb4d8e288d5264d1cadaf540ef0ca4794
Signed-off-by: Jee Hyeok Kim <jihyeok13.kim@samsung.com>
Signed-off-by: Jung Seungho <shonest.jung@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14781
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
(cherry picked from commit f1e992e402ce526f3b2d9b4dd769d91a9f8888d8)
Reviewed-on: https://gerrit.iotivity.org/gerrit/16087
Tested-by: jenkins-iotivity <jenkins@iotivity.org>