Cost Explorer API (6/n): summarize most costs from 2i2c infra: overview most costs from typical 2i2c AWS hubs' cloud infra

[consideRatio]

In order to track costs from 2i2c's AWS hubs' infrastructure, we need to acquire a very good overview. We are not starting from scratch on this, but it needs to be very explicit.

Definition of done

• A good sense of most costs incurred by 2i2c AWS hubs' infra is acquired
• An overview is written out, including if the various costs should be hub attributed or not.

[consideRatio]

With #4453 (comment), I consider this completed!