automation: fleet cluster groups tests

[yonasberhe23]

Summary

Fixes #rancher/qa-tasks#1362

• This PR reenables existing and adds new Fleet Cluster Groups tests.
• It also fixes a failure seen in Jenkins runs in Fleet Dashboard test

Fleet Dashboard -> can clone a git repo: AssertionError: Timed out retrying after 10000ms: Expected to find element: .vs__dropdown-menu > li, but never found it."

Checklist

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• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
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[izaac]

This is looking good, but the fleet tests are failing in the github pipeline.

[yonasberhe23]

This is looking good, but the fleet tests are failing in the github pipeline.

@izaac looks like those failures were cause by a recent change in rancher backend which requires a fix on our end. should be fixed by #13107