Websocket support

### Clear and concise description of the problem

As discussed in the meeting, I am opening an issue where we can start a discussion on the design how to best approach what support for websockets in TSP would look like and what are the downstream emitter implications.

cc @johanste , @bterlson , @trrwilson

### Checklist

- [X] Follow our [Code of Conduct](https://github.com/microsoft/typespec/blob/main/CODE_OF_CONDUCT.md)
- [X] Read the [docs](https://typespec.io/docs/).
- [X] Check that there isn't already an issue that request the same feature to avoid creating a duplicate.