Added logic for remove NSProvider.

Added logic for remove NSProvider.

When subscribe cancel API called by user,
information of target provider need to be removed in storage.

NSProvider is removed when user call subscribe cancel API.

Conflicts:
        service/notification/src/consumer/NSConsumerCommunication.c

Change-Id: I480f2253d3eb52af62bab01235ba5cb2888fda8a
Signed-off-by: KIM JungYong <jyong2.kim@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/9493
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Uze Choi <uzchoi@samsung.com>
Tested-by: Uze Choi <uzchoi@samsung.com>