[Enrollee] Implement ESSetState(), ESSetErrorCode() API & fix ESTerminateEnrollee...

[Enrollee] Implement ESSetState(), ESSetErrorCode() API & fix ESTerminateEnrollee() API

1. ESSetState(), ESSetErrorCode() API is added in easysetup.c

2. ESTerminate() API logic is changed in resourcehandler.c

3. Variable name of ErrorCode is changed. (ESLastErrCode -> ESErrorCode)

Change-Id: I3be46d75924bff137171b06f102ea74c3634beef
Signed-off-by: sy01.youn <sy01.youn@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/9143
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jihun Ha <jihun.ha@samsung.com>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>