Currently Assisted Service, when adding a new node, configure the bootstrap ignition to fetch the node ignition from the insecure port (22624), even though it would be possible to use the secure one (22623). This could be an issue for the existing users that didn't want to use the insecure port for the add node operation.

Implementation notes
Extend the ClusterInfo asset to retrieve the initial ignition details (url and ca certificate) from the openshift-machine-api/worker-user-data-managed secret, if available in the target cluster. These information will then be used by the agent-installer-client when importing a new cluster, to configure the cluster ignition_endpoint