✨ Allow overriding image name in clusterctl config

[alexander-demicev]

What this PR does / why we need it:
This PR adds a name override option for the clusterctl config:

images:
  cluster-api:
    repository: myorg.io/local-repo
    name: mirrored-cluster-api-controller
    tag: v1.10.6

We have use-case where using clusterctl config is the best option to override CAPI image name for some air-gapped scenarios where image is retagged with a slightly different name.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

/area clusterctl

[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 fabriziopandini for approval. For more information see the 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

[alexander-demicev]

/area clusterctl

[salasberryfin]

Thanks @alexander-demicev.

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: f0443ca25466e6ce217493cb8df62c259ca89dff

[k8s-ci-robot]

New changes are detected. LGTM label has been removed.