Added client sample for proxy

Added client sample for proxy

Removed proxy changes from csdk sample and
added separate sample for proxy.

Change-Id: I45b31b46ee61eee7dd440dad0b2957345a75b1d0
Signed-off-by: Abhishek Sharma <ce.abhishek@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/11869
Reviewed-by: jihwan seo <jihwan.seo@samsung.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>
(cherry picked from commit 02488c95057b3cf160ad60feea3b960352b36c70)
Reviewed-on: https://gerrit.iotivity.org/gerrit/11989
Reviewed-by: Uze Choi <uzchoi@samsung.com>