Separated transmission logic for data on Both Mode.

Separated transmission logic for data on Both Mode.

Since BLE transport has gatt server and client.
there are two sender and receiver
such as notifyCharacteristic / writeCharacteristic in BLE transport.
(while other transport has only one sender and receiver.)

thur, message has to be sent by message type which whether
it is a request or response message.

Change-Id: I7f77d86c13115138082b72a6371ce5bd49f1f0c6
Signed-off-by: jihwan.seo <jihwan.seo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/9255
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Jon A. Cruz <jon@joncruz.org>