ci: Update Scale Test images from docker to ACR/MCR

[jpayne3506]

Reason for Change:

Current iteration of Scale Test pipeline is not able to function properly as these images were being rate-limited by docker.

Additional improvements need to be made to this pipeline:

• Fail on bad image pull
• Check general cluster health before starting tests, failing if over a timeout
• Replace pipeline variables with new convention, clear out old variables
• Bump cluster creation podcidr to /12, standard tier for dedicated node, standard load balancer sku

Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• relevant PR labels added

Notes:

[github-actions]

This pull request is stale because it has been open for 2 weeks with no activity. Remove stale label or comment or this will be closed in 7 days

[github-actions]

This pull request is stale because it has been open for 2 weeks with no activity. Remove stale label or comment or this will be closed in 7 days

[github-actions]

Pull request closed due to inactivity.