dillon1000/react

[Flight] Remove back pointers to the Response from the Chunks (#33620)

This frees some memory that will be even more important in a follow up.

Currently, all `ReactPromise` instances hold onto their original
`Response`. The `Response` holds onto all objects that were in that
response since they're needed in case the parsed content ends up
referring to an existing object. If everything you retain are plain
objects then that's fine and the `Response` gets GC:ed, but if you're
retaining a `Promise` itself then it holds onto the whole `Response`.

The only thing that needs this reference at all is a
`ResolvedModelChunk` since it will lazily initialize e.g. by calling
`.then` on itself and so we need to know where to find any sibling
chunks it may refer to. However, we can just store the `Response` on the
`reason` field for this particular state.

That way when all lazy values are touched and initialized the `Response`
is freed. We also free up some memory by getting rid of the extra field.