move the cloudpipe_update API v2 extension to use objects

This change converts the cloudpipe_update extension to use the Network
object instead of direct database access.

Related to blueprint compute-manager-objects-juno

Change-Id: Ie4f800e05dae9aafd6f0f11ef0f2cd9ecf0d3215
Merge "move the cloudpipe_update API v2 extension to use objects"