Separate floating_ip_pools_client

As the qa-spec of consistent-service-method-names, we have decided
all service client modules will be separated into a single module
by each resource. So this patch separates floating_ip_pools_client
from floating_ips_client.

Partially implements blueprint consistent-service-method-names

Change-Id: I598cd20e85c671eae10d15e07b7f34c564be2ddc
6 files changed