Enhance: Enable O2 IMS for distributed cloud

1. Expand dcmanager client as SDK to support getting information of subcloud
2. Implementation of a client that can support distributed cloud
3. Resource pool sends a tag to all the resources that it has,
   to support the resource to get the correct client

Issue-ID: INF-263
Signed-off-by: Zhang Rong(Jon) <rong.zhang@windriver.com>
Change-Id: I1caa869339730c1d3d209e5624122dc825736c87