Incomplete chunk reading/writing for streams

[poshcoe]

Hi,

Thanks for making this library! I've been using xwt while developing a small WASM/native app and it's saved me a lot of time.

I see that there has been a start on supporting chunked reading/writing with the ReadChunk and WriteChunk traits in xwt-core, but it seems these are not implemented anywhere as of yet. (Am I missing something?)

What are the blockers for implementation of these traits within xwt-web-sys and xwt-wtransport?

I may be able to lend a hand.