Default MachineRegistration in Helm chart

[agracey]

Describe the solution you'd like:
It might be nice to provide a default Machine Registration object in the helm chart. This could reduce the installation and setup with one less step.

That way we can provide some basic setup in the helm chart install:

helm upgrade --create-namespace -n cattle-elemental-system --install elemental-operator \
  oci://registry.opensuse.org/isv/rancher/elemental/charts/elemental/elemental-operator \
  --set defaultReg.install.device=/dev/nvme0n1 --set defaultReg.install.powerOff=true --set defaultReg.MachineLabels[0]=<label>

In the future, we can even use the questions.yml functionality in Rancher to allow for exposing these in the Marketplace.

[kkaempf]

I marked this as later for now and would rather wait for actual market feedback.

What could be useful, however, is respective UI defaults.