support for embedding initial machine config

[smira]

This will be gated under Enterprise gate.

This should be available in any Image Factory flavor @Orzelius

[github-actions]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[github-actions]

This issue was closed because it has been stalled for 7 days with no activity.

[Orzelius]

done via #448