Export benchmark suite results to Grafana

[manno]

The motivation is to publish Fleet scalability test result on a centralized platform so we can analyze the evolution of Fleet performance over period of time.

There is already a project named rancher/dartboard which is a one-stop tool that doesn't fully work for Fleet. For example scalability tests are defined using k6 while the Fleet team uses Ginkgo

So instead of a one-stop tool, we would prefer an independent component that we can reuse on other Rancher project.

As a first step, the proposal is to export Fleet test result to a JSON format that can be then injected in the same services used by Dartboard, Grafana and Mimir. That JSON file should become the standard API to publish test result on the future platform.

Please note that JSON is not a strong requirement, and a better file format can be used as long as it's a generic format that we can use with other testing framework

Fleet benchmark tests are defined in here