defined in the new installer, use the equivalent component in `istio-system`, configured with the official installer, or use a different version or implementation. For example you may use your own Prometheus and Grafana installs, or you may use a specialized/custom certificate provisioning tool, or use components that are centrally managed and running in a different cluster. This is a work in progress - building on top of the multi-cluster installer. As an extreme, the goal is to be possible to run...