[JIRA IOT-778] fixed the jira issue related to CASendNotification API.

[JIRA IOT-778] fixed the jira issue related to CASendNotification API.

CASendNotification API is not used by RI layer.
RI layer is using CASendRequest API to send notification.
so we removed the CASendNotification API and modified the CA sample.

Change-Id: I90d490814dcd5e250564ca4f221911fb1c365128
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/3457
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Patrick Lankswert <patrick.lankswert@intel.com>