test(browser): add ReadableStream response body test

[kettanaito]

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[kettanaito]

Hey, @thepassle. I've added this browser integration test for a readable stream mock response body and it doesn't require setting the duplex option either. Could you give this a quick look if everything's alright? Thanks.

[thepassle]

Ah, the duplex is required in Request, not Response:

a = new Request('/api/foo', {
  method: 'POST',
  body: new ReadableStream()
});

results in:
Uncaught TypeError: Failed to construct 'Request': The duplex member must be specified for a request with a streaming body

See also: https://developer.chrome.com/articles/fetch-streaming-requests/#half-duplex

[kettanaito]

@thepassle, yeah, that's right. You need that option to send a readable stream. That needs no testing on MSW's side because the way you construct the request is up to you and it has to be correct. Thanks for verifying that 👍

[thepassle]

Yeah, looks like I got things mixed up :) my bad!