Added support for GCP in cost summary

[BSick7]

Summary

The Nullstone dashboard provides a monthly summary of costs.
This currently only supports AWS.
We should provide support for GCP.

Intended Outcome

How will it work?

Steps to configure Cost Reporting

1. Ensure "global" GCP project (where you normally hold your root DNS records)
2. Create
3. Go to console.cloud.google.com/billing
4. Select the primary billing account
5. Left nav -> Billing export
6. Enable "Standard usage cost"
   • Edit Settings
   • Select any project (usually "global"; whatever holds your root DNS records)
   • CREATE NEW DATASET > Dataset ID: billing_export > Click "Create dataset"
   • Choose created dataset and click "Save"
7. Enable "Detailed usage cost"
   • Edit settings
   • Choose same project as step 4 > choose same dataset > click "Save"
8. Go to