[tunnelbroker] Use Hyper service instead of tokio_tungstenite

Summary:
Replaces tokio_tungstenite usage with Hyper service that is implemented in D9158 - more detailed description in that diff.

Depends on D9158

Test Plan:
Tunnelbroker builds and runs. Integration tests work, I'm able to connect to the tunnelbroker websocket port.
Connecting by HTTP works as well - the /health endpoint is available and returns 200 OK. Other paths return 404.

Reviewers: kamil, michal, varun, jon

Reviewed By: michal

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D9160