function createByteStreamYielder
Swift
func createByteStreamYielder(streamId: UInt64, buffer: FlatBuffer, sendChunk: @escaping (FlatBuffer) -> Void, sendComplete: @escaping (UInt64, UInt64) -> Void) -> StreamYielder<UInt8>
Helper to create a byte stream yielder (most common case)
nprpc_swift/Sources/NPRPC/StreamReader.swift:833