perf(ext/web): convert hot stream queues to O(1) Queue, cache _state reads (#34437)

Three internal slots in the Web Streams implementation were backed by
plain
arrays and dequeued with `ArrayPrototypeShift`, which is O(n) and
re-allocates
the array's head on every removal: `WritableStream` `_writeRequests`,
`ReadableByteStreamController` `_pendingPullIntos`, and
`ReadableStreamBYOBReader`
`_readIntoRequests`. They are now backed by the same `Queue` class
already used
for `_readRequests`, so dequeue is O(1). This also removes a polymorphic
IC
between `_readRequests` (`Queue`: `.size` / `.dequeue()`) and
`_readIntoRequests`
(`Array`: `.length` / `shift`) in helpers that touch both reader kinds.

While here, repeated `stream[_state]` symbol reads in the hottest paths
(`readableStreamDefaultReaderRead`,
`readableStreamReaderGenericInitialize`,
`readableStreamCancel`) are hoisted into locals, and a redundant
`controller[_stream][_state]` chained read in
`readableByteStreamControllerEnqueue`
now reuses the already-cached `stream` local. Follow-up to #32652.

A new `tests/bench/streams.js` exercises the touched paths: default
reader
reads, many concurrent writes, the BYOB pull-into pipeline, and a
`TransformStream` pipe-through.