Multiple 'Set-Cookie' header within Header struct (VirtualService)

[fentas]

Describe the feature request
Regarding type Headers_HeaderOperations struct
https://github.com/istio/api/blob/master/networking/v1alpha3/virtual_service.pb.go#L793-L804

As the key of Add attribute reflects the header name, setting multiple keys/headers like Set-Cookie is impossible.
Is there a way to set multiple Set-Cookie headers like separating cookies definitions with , (tried and failed). This would require that istio would unfold this to separate header.

Describe alternatives you've considered

As I have the need to set 2 cookies right now I am doing kind of a workaround and set one within the Http struct and one into the Destination. This works and envoy delivers two separate Set-Cookie headers.

Affected product area (please put an X in all that apply)

[x] Configuration Infrastructure
[ ] Docs
[ ] Installation
[x] Networking
[ ] Performance and Scalability
[ ] Policies and Telemetry
[ ] Security
[ ] Test and Release
[ ] User Experience

Additional context

But we have the use case which would require to set more than 2 Cookies within one route.

[kuuji]

Any update on this? We're having the same issue and require setting multiple cookies.