Add metric_id to openapi definitions

As a GUI dev, I'd like to move away from UOM references in favor of metric_id, so that backend devs can remove UOM from the API, however, metric_id isn't available in all places that currently have UOM in the API

Done Criteria

• Significant QE Test refactor
• metric_id is included on the OpenAPI endpoints & populated where we are currently using UOM. This includes both query parameters & response bodies
• UOM IS NOT CHANGED AND IS NOT REMOVED
• There should be no breaking changes in this card
• metric_id on some endpoints is replacing an enum with a string, so that any valid metric_id can be used this includes the code that the openapi definition is calling (such as /subscriptpions/products/{product_id}).