Implement the Body trait for ChunkedBody

[Thomasdezeeuw]

Related code:

heph/http/src/body.rs

Lines 379 to 387 in 1af3172

	/// Streaming body with an unknown length. Send in multiple chunks.
	#[derive(Debug)]
	pub struct ChunkedBody<'b, B> {
	#[allow(dead_code)] // Currently unused, but need for the `Body` impl.
	stream: B,
	_body_lifetime: PhantomData<&'b [u8]>,
	}
	// TODO: implement `Body` for `ChunkedBody`.