Router should include ws_route_class

[jimcarreer]

Is your feature request related to a problem

Yes. I use a router + route_class to apply custom logic to ALL routes in my application. Currently the route_class argument does not apply to websockets (this appears to be by design).

The solution you would like

Similar to the route_class argument of a Router there should be a ws_route_class to provide the same kind of plug-able behavior for websockets.

Describe alternatives you've considered

I've looked around a bit in the documentation but don't see any specifics on how to do this. Middleware is not appropriate as I add additional context to specific endpoints using custom decorators, the endpoint that is to be called eventually by the request is not available to me at the point in time middleware logic is applied.

[jimcarreer]

Also, I think this is a feature I could add myself, however I wanted to make sure I wasn't missing something about Router+route_class usage before I submit a PR.