feat: support packet splitting and multi-stream parallel transmission

[shjwudp]

No description provided.

[todo]

Consider dynamically assigning tasks to make the least stream full

bagua-net/src/bagua_net.rs

Lines 357 to 362 in 79fed32

	// TODO: Consider dynamically assigning tasks to make the least stream full
	parallel_streams.push(std::thread::spawn(move || {
	let out_timer = std::time::Instant::now();
	let mut sum_in_time = 0.;
	for (data, state) in msg_receiver.iter() {
	let in_timer = std::time::Instant::now();

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This comment was generated by todo based on a TODO comment in 79fed32 in #5. cc @BaguaSys.

[shjwudp]

@NOBLES5E README modified and ready to review.