[Feature] Ability to expose the SSH credentials before waiting OCP readiness

[kpouget]

Currently, mapt generates the secrets at the end of the deployment.

However, if the step main-ocp-readiness-aos-cmd never completes (because of a bug in the systemd launcher), one cannot access the cluster to troubleshoot it.

Would be nice if mapt could dump:

• the hostname
• the ssh private key
• (the username)

at the end of the main-ssh-readiness-aos-cmd step.

Workaround is to run with the --debug flag to see the private key, and get the instance public IP from AWS console.