Implement wasi-sockets in Wasmtime

[kulakowski-wasm]

• Update wasi-sockets to use streams instead of push/pullbuffer

[spacewander]

Is there any update for the wasi-sockets support?

[huangjj27]

maybe releated to #4776

[abrown]

I think we should close this: sockets are implemented in wasi-common as of #4776. The switch to streams from buffers is pushed to a later date, I think (@sunfishcode?), so for clarity's sake it would be better to mark this done until that switch happens.

[sunfishcode]

Wasmtime does have support for the sock_accept sockets API that was added to preview1.

"wasi-sockets" refers to this preview2 proposal, which wasmtime doesn't support yet, though we are working on it.

[badeend]

I think this can be closed now