test(mc): initial multicloud IaC boilerplate GKE, AKS, Kind

[SRodi]

Description

Initial work on multi-cloud

• create modules for aks, gke, kind and retina
• use gcloud, azure, kind and helm providers
• create examples on how to use each module
• create automated tests in Go Terratest for each module example (only initial work, since we require creds for public clouds)
• create a Makefile for this subproject
• create GH workflow with automated tests

Related Issue

#1267

Checklist

• I have read the contributing documentation.
• I signed and signed-off the commits (git commit -S -s ...). See this documentation on signing commits.
• I have correctly attributed the author(s) of the code.
• I have tested the changes locally.
• I have followed the project's style guidelines.
• I have updated the documentation, if necessary.
• I have added tests, if applicable.

Screenshots (if applicable) or Testing Completed

All modules were tested and work as expected.

See automated tests here https://github.com/microsoft/retina/actions/runs/12993893617/job/36237118572

Additional Notes

Add any additional notes or context about the pull request here.

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Please refer to the CONTRIBUTING.md file for more information on how to contribute to this project.

[alexcastilio]

LGTM... I'll not approve it now to wait for more feedback from others