✨ Add clusterctl changes for cross-ns CC ref

[Danil-Grigorev]

What this PR does / why we need it:
This PR allows clusterctl to create a template with a reference to CC located in a different namespace.
This change allows to perform e2e tests in a multi-ns environment.

Added e2e tests to verify cluster-class quick-start scenario and runtime extension scenario in a cross-namespaced context.

The PR is built on top of:

• 🐛 Use namespace of the reference on external.Get #11361
• ✨ Add classNamespace to topology #11352

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 #5673

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