[stress testing] Use local stress-test-addons reference in dev environment

[benbp]

When using dev environments for stress testing, the environment values get added to stress-test-addons values.yaml. Any charts with a dependency on addons that lookup values from the env will fail by default because they will try to download the upstream stress-test-addons dependency. For local testing, we should detect a dev environment (more specifically, an environment that is not test or prod), and update the Chart.yaml dependency to reference a file path.

For example this:

dependencies:
- name: stress-test-addons
  version: 0.1.12
  repository: https://stresstestcharts.blob.core.windows.net/helm/

Becomes:

dependencies:
- name: stress-test-addons
  version: 0.1.12
  repository: file:///Git/azure-sdk-tools/tools/stress-cluster/cluster/kubernetes/stress-test-addons

This behavior should also be opt-out in case we need to test non-local chart versions of addons in a dev environment. The parameter needs to work for both provision and deploy stress tests.