[Flight] Add Debug Channel option for stateful connection to the backend in DEV (#33627)

This adds plumbing for opening a stream from the Flight Client to the
Flight Server so it can ask for more data on-demand. In this mode, the
Flight Server keeps the connection open as long as the client is still
alive and there's more objects to load. It retains any depth limited
objects so that they can be asked for later. In this first PR it just
releases the object when it's discovered on the server and doesn't
actually lazy load it yet. That's coming in a follow up.

This strategy is built on the model that each request has its own
channel for this. Instead of some global registry. That ensures that
referential identity is preserved within a Request and the Request can
refer to previously written objects by reference.

The fixture implements a WebSocket per request but it doesn't have to be
done that way. It can be multiplexed through an existing WebSocket for
example. The current protocol is just a Readable(Stream) on the server
and WritableStream on the client. It could even be sent through a HTTP
request body if browsers implemented full duplex (which they don't).

This PR only implements the direction of messages from Client to Server.
However, I also plan on adding Debug Channel in the other direction to
allow debug info (optionally) be sent from Server to Client through this
channel instead of through the main RSC request. So the `debugChannel`
option will be able to take writable or readable or both.

---------

Co-authored-by: Hendrik Liebau <mail@hendrik-liebau.de>

scripts/error-codes/codes.json

@@ -548,5 +548,7 @@
   "560": "Cannot use a startGestureTransition() with a comment node root.",
   "561": "This rendered a large document (>%s kB) without any Suspense boundaries around most of it. That can delay initial paint longer than necessary. To improve load performance, add a <Suspense> or <SuspenseList> around the content you expect to be below the header or below the fold. In the meantime, the content will deopt to paint arbitrary incomplete pieces of HTML.",
   "562": "The render was aborted due to a fatal error.",
-  "563": "This render completed successfully. All cacheSignals are now aborted to allow clean up of any unused resources."
+  "563": "This render completed successfully. All cacheSignals are now aborted to allow clean up of any unused resources.",
+  "564": "Unknown command. The debugChannel was not wired up properly.",
+  "565": "resolveDebugMessage/closeDebugChannel should not be called for a Request that wasn't kept alive. This is a bug in React."
 }