Investigate adding more structure to rates.yaml

[QuanMPhm]

As pointed out by @larsks, the rates.yaml now contains not only SU rates, but a variety of other types of metadata, making it impossible to use without substantial external knowledge (such as what types of SUs are available? what kind of resources of they have? etc) This has forced us to hardcode certain information in our billing repos (i.e the list of SUs in Openstack billing), increasing our maintenance burden whenever we introduce another SU type.

As suggested by @larsks, we should see how the rates.yaml file can be restructured.

@knikolla @naved001 Let me know your thoughts

[QuanMPhm]

@naved001 I remember last week you did mention that certain cluster-specific information (i.e the mapping between SUs and their resource names on the actual Openstack cluster and what appears in invoices) may still need to hardcoded in their respective billing repos. I think that information can be also be put in rates.yaml, at the cost of making the data structure much more complex.

[naved001]

@QuanMPhm haha I just finished typing that in a comment on a different thread:

CCI-MOC/bare-metal-usage-scripts#1 (comment)