Return complete resp from security_group_rules_client

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

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 security_group_rules_client to return
complete Response body.

Change-Id: If0914462b742d4d4c69a9a2e5da8c874acdf5c7f
Implements: blueprint method-return-value-and-move-service-clients-to-lib
5 files changed