wip: feat(capi): add support for external cert-manager module

[floreks]

Summary

This updates CAPI cluster bootstrap and migrate to work with external cert-manager module.

Depends on pluralsh/plural-artifacts#829

TODO:

• Update recipes to depend on external cert-manager module after the above PR gets merged

Test Plan

Tested on GCP. Azure/AWS tests should follow.

Fresh CAPI deploy

Pre: The test recipe needs to be updated with a new cert-manager section.

  - name: cert-manager
    configuration: []
    items:
      - type: HELM
        name: cert-manager
      - type: TERRAFORM
        name: gcp
      - type: TERRAFORM
        name: kube

1. Link bootstrap helm module from plural-artifacts (required only until it gets merged).
2. Bootstrap CAPI cluster.

Migration

1. Bootstrap standard TF-based cluster.
2. Link bootstrap helm module from plural-artifacts (required only until it gets merged).
3. Run plural clusters migrate. It should install cert-manager into cert-manager namespace at the end and remove old installation from bootstrap namespace.

Checklist

• If required, I have updated the Plural documentation accordingly.
• I have added tests to cover my changes.
• I have added a meaningful title and summary to convey the impact of this PR to a user.
• I have added relevant labels to this PR to help with categorization for release notes.