✨ ROSA: Generate CAPI kubeconfig secret

[muraee]

What type of PR is this?
/kind feature

What this PR does / why we need it:

This PR generates a kubeconfig secret for ROSA clusters according to CAPI contract

Secret name	Field name	Content
<cluster-name>-kubeconfig	value	base64 encoded kubeconfig

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 #4734

Special notes for your reviewer:

Checklist:

• squashed commits
• includes documentation
• includes emojis
• adds unit tests
• adds or updates e2e tests

Release note:

Generate CAPI kubeconfig secret for ROSA clusters

[k8s-ci-robot]

Hi @muraee. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[vincepri]

/ok-to-test

[vincepri]

/approve
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: vincepri

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