feat: if marker is not defaulted it should be marked as required

[scottd018]

If a marker does not have a default value, the marker should be marked as a required value. It should look like this in the apis/<GROUP>/<VERSION>_types.go generated file:

	// +kubebuilder:validation:Required
	// Description of the service account goes here.
	ServiceAccount string `json:"serviceAccount"`

The following from above is relevant:

1. The +kubebuilder:validation:Required should be added above the description.
2. The omitempty tag should be missing (on the serviceAccount line)
3. This should only apply to the end of a struct (e.g. google.serviceAccount is applicable google.serviceAccount.name is not applicable)