streams: refactor ReadableStream asyncIterator creation and a few fixes

Closes: https://github.com/nodejs/node/issues/23041

- Rewrite `ReadableAsyncIterator` class into
`ReadableStreamAsyncIteratorPrototype` which contains no constructor and
inherits from `%AsyncIteratorPrototype%`.

- Rewrite `AsyncIteratorRecord` into dumb function.

PR-URL: https://github.com/nodejs/node/pull/23042
Fixes: https://github.com/nodejs/node/issues/23041


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>