Load testing the Operator - early output

[lawrencegripper]

With the work on #104 to add Metrics into Prometheus we've been able to combine this with a locust loadtest and the run some early tests with a mocked databricks API and graph the k8s-api-server, locust-metrics and databricks-operator-metrics to see how things scale.

Very early days but I'd be interested to know how much of this work you'd like to see contributed back to the project.

Shout out to the team for their work here @stuartleeks @EliiseS @martinpeck and @storey247