Capture logging as seen by the user in agent-gather output

When we need debugging information from a user, we ask them to run the agent-gather command on one or more of the hosts and send us the output. Quite often, we also want to see the output from running the openshift-install agent wait-for install-complete command. While all issues that are apparent from the installer output can theoretically be diagnosed from the node logs, sometimes the installer output makes it much more obvious.

To help us see what the user is seeing, start a systemd service on Node 0 that runs openshift-install agent wait-for bootstrap-complete so that the output is captured in the journal. The openshift-install binary is available in a container in the release image (and can be run directly in that container).

This will require having an asset store file containing at least the InstallConfig, AgentConfig, and AgentManifests in the ISO, which is a probably not a bad thing to have in the agent-gather output also. However, we will need to take care to redact the user's pull secret from both the InstallConfig and AgentManifests if including this data in the agent-gather.