modify resouce-encapsulation sample server and client

modify resouce-encapsulation sample server and client

sampleResourceClient
- add the function that discover resouce
- add the function that cancel discover resource

sampleResourceServer
- select presence mode
- select resource type

Change-Id: I9e5867569be687fc25a9d1eca7a2cdff585b2963
Signed-off-by: ChaJiwon <jw_wonny.cha@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/2631
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>