Add CASetCloudAddressForProxy method

Add CASetCloudAddressForProxy method

[Model] IoTivity
[BinType] AP
[Customer] IoT-Core

[Issue#] CONPRO-1393
[Request] Robert Chudek / r.chudek
[Occurrence Version] n/a

[Problem] IoT-Core needs a method to set cloud address for proxy.
[Cause & Measure] Cause: No such method implemented.
[Checking Method] n/a

[Team] IoT Connection
[Developer] Robert Chudek / r.chudek
[Solution company] Samsung
[Change Type] new feature

https://github.sec.samsung.net/RS7-IOTIVITY/IoTivity/pull/415
(cherry picked from 0689b92fdb5dc0018768cf36b1723f2f55a9395c)

Change-Id: Icc3f706a5e929fcddb32ffebea20070db2ba5680
Signed-off-by: Abhishek Sansanwal <abhishek.s94@samsung.com>