Create performance testing foundation w/ k6

[scotwells]

Summary

Create a performance testing foundation using k6 and the k6-operator for test orchestration. The performance test should load documents into Meilisearch through the indexing pipeline and then execute search queries as a user.

We should document the observed performance of the service as a baseline.

Acceptance Criteria

• Create performance tests using k6
• Create kustomize component that can load the perf tests into a k8s cluster to run with k6-operator
• Execute performance tests in production-like environment and document results
• Bonus points if we can automatically run these end-to-end tests in the CI pipeline.