[Jan Egil Ring (janegilring)]

This pull request focuses on improving the reliability and clarity of AKS (Azure Kubernetes Service) deployments with Istio service mesh, as well as refining role assignment logic and associated tests. The most significant changes include explicitly specifying an empty Istio profile in the Bicep template, updating deployment documentation, and tightening test and script logic for role assignments.

AKS Istio Service Mesh Improvements:

• main.bicep: Explicitly adds an empty istio object to serviceMeshProfile when mode is Istio, ensuring compliance with the managed-cluster API and preventing deployment ambiguity.
• README.md: Updates deployment documentation to clarify that deployment success can be inferred from offline tests or ARM validation, explains the rationale for the explicit Istio profile, and adds guidance on handling quota and subscription errors.

Role Assignment Logic and Testing:

• deploy-lab.ps1: Removes the unnecessary --all flag from the role assignment list command, making role assignment queries more efficient and less error-prone.
• console.Tests.ps1: Updates tests to assert the absence of the --all flag and the presence of the --scope parameter in role assignment commands, ensuring the script changes are validated.

Bicep Template Validation:

• console.Tests.ps1: Adds tests to verify that the generated AKS template includes the istio property as a pscustomobject and that the property name is present, confirming the template change is effective.