Ensure that failed request tracing is enabled for Azure App Service

Azure App service has failed request tracing disabled, this may make audit challenging.

In Azure Console -

1. Open the Azure Portal and go to App Services.
2. Select the App service you wish to edit (the setting only applies to Windows app services).
3. Select App Service Logs under Monitoring.
4. Set Failed request tracing to On.
5. Save.

In Terraform -

1. In the azurerm_app_service resource, set failed_request_tracing_enabled to true.

References:
https://learn.microsoft.com/en-us/azure/app-service/troubleshoot-diagnostic-logs
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/app_service#failed_request_tracing_enabled