[FEATURE REQ] Support lambdas in Azure.Provisioning

[eerhardt]

Library name

Azure.Provisioning

Please describe the feature.

When trying to allow my ACA app to talk to my Azure Storage account, I need to be able to set the list of ipRules on the networkAcls:

resource storageAccountUpdate 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: storageAccountName
  location: location
  properties: {
    networkAcls: {
      ipRules: map(web.properties.outboundIpAddresses, ip => { value: ip, action: 'Allow' }) 
      virtualNetworkRules: []
      bypass: 'AzureServices'
      defaultAction: 'Deny'
    }
  }
}

This isn't possible in Azure.Provisioning today. It would be great if we could support emitting lambda expressions like this using BicepExpression.

cc @tg-msft