CAPI image name doesn't conform to scs-0102-v1 / incompatible with openstack-image-manager

/kind bug

What steps did you take and what happened:
Workload clusters created with cluster stacks will use node image names such as

ubuntu-capi-image-v1.28.11

instead of

ubuntu-capi-image v1.28.11

The latter is what the scs-0102-v1 and scs-0104-v1 require (note the space instead of the dash).

This means that a compliant public image such as ubuntu-capi-image v1.28.11 uploaded by an operator will not be used for the K8s nodes. Instead, an image will be uploaded on-the-fly (if it wasn't uploaded during a previous run) and marked as private. This image is missing a lot of the properties that are usually set, such as image_source (already reported in #23). Also, since qcow2 seems to be used, in the case of Ceph this will circumvent the ability to use copy-on-write RBD clones and use a lot of space.

What did you expect to happen:
For Kubernetes vX.Y.Z, cluster stacks should use ubuntu-capi-image vX.Y.Z as the image name.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Kubernetes version: (use kubectl version)
• OS (e.g. from /etc/os-release):

Start by tracing how cluster stacks generate node image names for workload clusters, then compare the generated name with the scs-0102-v1 and scs-0104-v1 standards linked in the issue. Done means Kubernetes vX.Y.Z uses the required ubuntu-capi-image vX.Y.Z name so an existing compliant public image is selected instead of a private image being uploaded.