Add support for WebStreams

## Background

I'm exploring verified (trustless) retrieval of CAR files (See https://github.com/olizilla/ipfs-get/issues/15) in browsers.

I discovered that there's no way to instantiate a CarReader from a [ReadableStream](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream) returned from the Fetch API in the browser.

This is because Readable Web Streams are not iterable by default.

## Adding support for Web Streams

For us to be able to promote verified retrieval in browsers, it would be nice to have full CAR support in browsers. For this, we need a way to instantiate a CAR Reader in the browser from a Readable Web Streams.

My current work around is to use @achingbrain's [browser-readablestream-to-it
library](https://github.com/achingbrain/it/tree/master/packages/browser-readablestream-to-it)

## Update 2025

No longer necessary. See https://github.com/ipld/js-car/issues/120#issuecomment-2576358304