Use specific URL for the reload web socket

[garyb]

I'm using live-server to serve static files and then have it proxying an API also, that API has a web socket endpoint, but it's unreachable at the moment as any web socket connection attempts made to the live-server will be grabbed by the reload socket.

This PR gives the reload socket endpoint in the injected code a slightly less generic name (in the hopes of avoiding potential overlaps) and adds a check to only connect the reload handling stuff if the request matches the name, allowing middleware or other things to pick up other socket requests as necessary.