Adds a method to `azure_cloud_provider` to query the Cost Management API
for usage data per invoice. For now, this query is relatively static.
We're always calling the API at the billing invoice section scope,
with the widest timeframe possible (one year), and with the same
requested dataset. As the scope of the application's reporting needs
changes, this function may change to be more general and/or revert back
to the SDK.
ff842f5051