tests: refactor fake objects init
tests: refactor fake objects init

Split out the creation of the PVC and VolumeOptions structures to increase
reusability.

Signed-off-by: Adam Litke <ed9d9846a37e30d0259dba27fda9320ea24a6102@redhat.com>

kubernetes/cloud-provider-openstack,kubernetes/cloud-provider-openstack,kubernetes/cloud-provider-openstack