Handling of missing parent property in collection response

Handling of missing parent property in collection response

In case parent is not included in the response. It creates an empty representation.
The first node is not considered parent.

Change-Id: I088a2bdb552cf6b75e67cc2f16fb9150878d717d
Signed-off-by: Jay Sharma <jay.sharma@samsung.com>
Signed-off-by: Habib Virji <habib.virji@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/15879
Reviewed-by: Harish Marappa <h.marappa@samsung.com>
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>