Add an callback for EasySetup resource in case of "connect" method

Add an callback for EasySetup resource in case of "connect" method

A new property, "connect", is managed in EasySetup resource, which can handle
POST operation. For that, an additional callback gets to be needed for
EasySetup resource.

Change-Id: I34d5ddeb7f9f1469b992099e75bed78ee3450bab
Signed-off-by: Jihun Ha <jihun.ha@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/17067
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Uze Choi <uzchoi@samsung.com>
Tested-by: Uze Choi <uzchoi@samsung.com>