I think it would be nice that we add websocket to the nework module, because normaly to use a websocket in c++ you either have to include a whole network library on the side of sfml network module just for the websocket or you can do your own wrapper out of libwebsocket which doesn't look fun to do/use.
Also since websocket are based on HTTP it could be a good thing to update sfml HTTP at the same time
... Or we can just wrappe libwebsocket and forget about HTTP