Display private cloud billing data

With https://abiquo.atlassian.net/wiki/spaces/doc/pages/406749275Abiquo automatically displays on-premise billing data on the cloud dashboards.

In versions prior to Abiquo 6.1, to display private cloud billing data on the Abiquo billing dashboard, you can use the private billing module with the Abiquo billing integration. See https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652344667.