Test the Gophercloud v3 Client interface

[pierreprinetti]

What this PR does / why we need it:

This PR tests the proposal Gophercloud v3 Client interface. First I'll test whether CAPO compiles with the proposed Gophercloud code, then I'll investigate replacing the Gophercloud test wrappers.

TODOs:

• squashed commits
• if necessary:
  • includes documentation
  • adds unit tests

/hold

[k8s-ci-robot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign jichenjc for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[netlify]

✅ Deploy Preview for kubernetes-sigs-cluster-api-openstack ready!

Name	Link
🔨 Latest commit	238a264
🔍 Latest deploy log	https://app.netlify.com/sites/kubernetes-sigs-cluster-api-openstack/deploys/6706695d9b47ee00084c61bf
😎 Deploy Preview	https://deploy-preview-2186--kubernetes-sigs-cluster-api-openstack.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[k8s-ci-robot]

PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.