Return complete response from floating_ips_client

Currently compute floating_ips_client returns Response by removing
top key from Response.
For example-
return service_client.ResponseBody(resp, body['floating_ip'])

As service clients are in direction to move to Tempest-lib, all
service clients should return Response without any truncation.
One good example is Resource pagination links which are lost with current
way of return value. Resource pagination links are present in parallel
(not inside) to top key of Response.

This patch makes compute floating_ips_lient to return complete
Response body.

Implements: blueprint method-return-value-and-move-service-clients-to-lib

Change-Id: Ib11e815a944321589dd618c7696249f0e0eb3938
16 files changed