Make ports_client use common waiter method

wait_for_resource_deletion() of network_client is used only for
ports_client and Tempest has a common waiter method in its rest
client. So this patch makes ports_client use the method and removes
network_client module for the cleanup.

Partially implements blueprint consistent-service-method-names

Change-Id: I3145163621dbf7c053f040d4c75b1dd16770ba55
18 files changed