Enable Workload Identity

[Gordonby]

As per this new bicep property https://docs.microsoft.com/en-us/azure/templates/microsoft.containerservice/2022-06-02-preview/managedclusters?pivots=deployment-language-bicep#managedclustersecurityprofileworkloadidentity

We should allow installation of workload identity through AKS resource creation

  properties: {
    securityProfile: {
      workloadIdentity: {
        enabled: bool
      }
    }
  }