Convert `Ignition` v2.x to v3.x to support CAPBK

[defo89]

What would you like to be added:
CAPI kubeadm-bootstrap controller creates v2 ignition which is legacy and not supported in modern operating systems without backwards patch.

Ignition v3 support was not added due to upcoming bootstrap redesign which still did not happen.

Explore an option to convert v2 to v3 ignition with: https://github.com/coreos/ign-converter

Alternatively, we keep an eye on CAPI bootstrapping separation topic and track upstream Ignition v3.x support

[hardikdr]

I would rather wait for CAPBK to support Ignition v3 instead of boot-operator converting it on the fly. Let's keep the issue open as a placeholder to track if and when that happens.

For the short term, currently, the CAPI-Metal provider consumes a specialized ignition-legacy package from Gardenlinux that can interpret the Ignition V2.