Support recent graphql-ws protocol version

[BerkliumBirb]

Right now websocket server uses Data, Start, and Stop client messages instead of Next, Subscribe, and Complete respectively described in graphql-ws Protocol

[github-actions]

Looks like this issue has been open for 6 months with no activity. Is it still relevant? If not, please remember to close it.

[fordN]

Websocket support is deprecated.