Streaming in wasm doesn’t work

[irevoire]

Currently, when streaming documents in wasm, we actually collect everything in RAM before sending it:

meilisearch-rust/src/reqwest.rs

Lines 80 to 100 in 437649f

	// TODO: Currently reqwest doesn't support streaming data in wasm so we need to collect everything in RAM
	#[cfg(not(target_arch = "wasm32"))]
	{
	let stream = ReaderStream::new(body);
	let body = reqwest::Body::wrap_stream(stream);
	request = request
	.header(header::CONTENT_TYPE, content_type)
	.body(body);
	}
	#[cfg(target_arch = "wasm32")]
	{
	use futures::{pin_mut, AsyncReadExt};
	let mut buf = Vec::new();
	pin_mut!(body);
	body.read_to_end(&mut buf)
	.await
	.map_err(|err| Error::Other(Box::new(err)))?;
	request = request.header(header::CONTENT_TYPE, content_type).body(buf);
	}

This is because reqwest doesn’t provide the wrap_stream method, see: seanmonstar/reqwest#2248