fix(cu): handle hashing wasm memory >2GB

[TillaTheHun0]

/**
 * The memoryStream, if derived from an iterable like a Buffer,
 * may emit the entire data stream as a single chunk.
 *
 * This can break things like Crypto hash, which can only handle
 * data chunks less than 2GB.
 *
 * So we use this Transform stream to receive chunks,
 * then re-emit "sub-chunks" of the given size -- in this case
 * the default highWaterMark of 64kb
 *
 * This allows for hashing to work for any size memory, derived
 * from any iterable, while respecting backpressure
 */