Persisted queries over websocket

[nyvid]

Hello guys,
With the subscriptionExchange it is possible to handle all operations over websocket connections. Is it possible or planned to support persisted queries over this exchange too? graphql-ws supports it (enisdenjo/graphql-ws#37 (comment))

[kitten]

That's a good point. While I would've asked you to write an RFC, I had some implementation and cleanup notes in mind, so I wrote up an RFC in your stead: #2989

I think this is a pretty overdue feature, so we could do this pretty easily.