### Description

This makes several changes to our HMR protocol to make play nicely with
Next's already existing websocket and protocol:
1. Use a `turbopack-` prefix in our message's `type`
2. Allow any compatible `sendMessage` and `addMessageListener`
implementation (so we can reuse Next's websocket handlers)
3. Create a new "dev client" entrypoint so that we can precompile with
NCC
4. Receive a pre-parsed `data` from the websocket's `message.data`
string.



### Testing Instructions

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Closes WEB-1452