Deprecate .spec.uuid in favor of .spec.systemUUID

[afritzler]

Summary

Since the system uuid is currently stored in the Server spec under uuid and leads to some confusion regarding the meaning of this field we might want to rename it. Suggestion would be to use .spec.systemUUID instead of .spec.uuid.

For backward compatibility we should deprecate the old field name and set both fields for now. Later we can set it to an empty string and remove it.

[stefanhipfel]

+kubebuilder:deprecatedversion can only bet set at the crd level, not field level.

so as far is I understand, one can only put it like this:

//+kubebuilder:deprecatedversion:warning="metal.ironcore.dev/v1alpha1 ServerSpec.UUID will be deprecated in version metal.ironcore.dev/v1alpha2, use ServerSpec.SystemUUID instead"