[IOT-1440] findResource() to return list of discovered resources.

[IOT-1440] findResource() to return list of discovered resources.

OCPlatform::findResource() does not return all the discovered resources in single callback
even though it gets the whole discovery payload from RI C layer.

This change implements OCPlatform::findResourceList() API which does return all the parsed
resources in discovery payload in single callback.

Change-Id: Ic95541f7303a15eb676029e6f2ea4952e5e3ca3e
Signed-off-by: Harish Kumara Marappa <h.marappa@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/13111
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
Reviewed-by: Abhishek Pandey <abhi.siso@samsung.com>
Reviewed-by: Ziran Sun <ziran.sun@samsung.com>