[IOT-1556] Changes in cloud according to the stateless request/response model (group...

[IOT-1556] Changes in cloud according to the stateless request/response model (group features)

The cloud implementation is revised, due to the protocol update to the stateless request/response model in the device-to-cloud communication.

- Group Management
  - Group creation implementation
  - add/update/delete properties
  - delete group
  - get group information

patch #6: POST /oic/acl/group/ response correction

Change-Id: I7db5836bff5b4cb33a7effa523f9388ff4240262
Signed-off-by: yeonghun.nam <yeonghun.nam@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14333
Reviewed-by: Jee Hyeok Kim <jihyeok13.kim@samsung.com>
Tested-by: Jee Hyeok Kim <jihyeok13.kim@samsung.com>