Fixed error handling at function of AddScene.

Fixed error handling at function of AddScene.

Fixed bug of exception handling to Add Same Scene.
If add scene as already exist value, It is ignored now.
When the patch is merged, throw exception.

Added get function of target resource uri of Scene member resource.
Fixed bug of call CA function before initialize Stack at Scene Collection Resource Class.

Change-Id: I7f72d7dfef541ae680a47d2d386a39ec674c4871
Signed-off-by: jyong2.kim <jyong2.kim@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/5179
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Uze Choi <uzchoi@samsung.com>