Customer-specified "InfraID" provided to install-config.yaml

1. Proposed title of this feature request

Customer-specified "InfraID" provided to install-config.yaml

2. What is the nature and description of the request?

The Kubernetes Cloud Controller Manager (cloud-controller-manager) and AWS Load Balancer Controller (aws-load-balancer-controller) query a cluster's subnets to identify them. This query uses the following tag as a filter:

kubernetes.io/cluster/<cluster-id>

The OCP installer generates an "InfraID", and then uses this value to fill in the <cluster-id>.

The problem with this, especially for managed clusters (ROSA, OSD, ARO), is that the "InfraID" value isn't known prior to creating the cluster, and if these customers are precreating their cloud infrastructure (subnets), they don't know what values to tag them with until they've already started provisioning the cluster.

Our request, from the managed services perspective, is to provide a unified experience. We would like to offer the ability for customers to specify their own value for what should be used as the "InfraID", and then allow us to propagate that through to the installer.

This is a value already exposed to us for Hosted Control Plane (HyperShift) clusters, and so we're looking for a similar mechanism on OCP Standalone cluster installations.