Build out scenario for Usage tracking

[lucashuet93]

Please provide us with the following information:

This issue is for a: (mark with an x)

- [ ] bug report -> please search issues before submitting
- [x] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Expected/desired behavior

• include load scripts
• have 2 separate groups of requests, differentiate using headers?
• have a query to build out graph/table depicting the consumption of the 2 groups.

[lucashuet93]

PR adds the e2e test that simulates load and sends requests using 3 different keys. Visualization of the usage data from test + cronjob (function?) that runs nightly and totals usage data for org units are still needed.

[lucashuet93]

Visualization should include new token metrics emitted post addition of <azure-openai-emit-token-metric /> policy

[lucashuet93]

Visualization includes as part of #26