Implement validation webhook call forwarding to OpenStackBaremetalSetSpec

[gibizer]

The OpenStackBaremetalSet CR has its own validation webhook. The OpenStackBaremetalSetSpec is included in the OpenStackDataPlaneRoleSpec validation of the OpenStackDataPlaneRoleSpec should also cal the validation of the OpenStackBaremetalSetSpec so that the user can get the validation issues right at the API response when creating OpenStackDataPlaneRole CR.

There is documented pattern to follow, see: openstack-k8s-operators/dev-docs#47

dataplane-operator/api/v1beta1/openstackdataplanerole_types.go

Lines 35 to 37 in 49de037

	// +kubebuilder:validation:Optional
	// BaremetalSetTemplate Template for BaremetalSet for the Role
	BaremetalSetTemplate baremetalv1.OpenStackBaremetalSetSpec `json:"baremetalSetTemplate,omitempty"`

[gibizer]

Please note that this probably needs changes in the baremetal-operator api module too.