CAPO currently only support ServerGroupID while the installer uses servergroupName on the machine definition.

https://github.com/openshift/installer/blob/master/pkg/asset/machines/openstack/machines.go#L257C21-L257C36
https://github.com/kubernetes-sigs/cluster-api-provider-openstack/blob/a8739340217e4dc0a85011f8606c747021327c92/api/v1alpha7/openstackmachine_types.go#L94

This is critical for integration with the installer work. Because the CAPO manifests will be generated before the server group is created, it is not possible to specify the server group UUID in the manifests. Without this change it is not possible to use a server group for the control plane machines.