Fix an faulty logic in resource handler and clean up useless codes

Fix an faulty logic in resource handler and clean up useless codes

1. In resourcehandler, a logic of encoding array type's property is fixed.
2. Remove a useless logic to send a GET request before a POST request for
   update of WiFi and devConf properties in EnroleeResource
3. Change country property's key --> ctry
4. Clean up old structure and enum variable not used anymore.
5. Remove a csdk for mediator which is not used anymore

Change-Id: I7502e6b33860db1bcc91a67829ac9411ff9cae6d
Signed-off-by: Jihun Ha <jihun.ha@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/9241
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>