title: How to send multipart/form-data with antd upload react
body: <p>I am using react and antd.<br>
  The component I am using from antd is <a href="https://ant.design/components/upload" rel="nofollow noreferrer">Drag and Drop</a>.<br>
  I am trying to send multipart/form-data using FormData object.<br>
  It sends the file (.zip file that should be sent as blob) but it does not send it as blob nor anything related to the other keys and values.<br>
  Here's a <a href="https://codesandbox.io/s/j3q07kyy8w" rel="nofollow noreferrer">Sandbox</a>.  </p>
  
  <p><strong>Expected Request Payload:</strong>  </p>
  
  <pre><code>------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  Content-Disposition: form-data; name="file"; filename="aFileName.zip"
  Content-Type: application/octet-stream
  
  [0,1,2]
  ------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  Content-Disposition: form-data; name="x2"
  
  y2
  ------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  Content-Disposition: form-data; name="x3"
  
  true
  ------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  Content-Disposition: form-data; name="x4"
  
  2
  ------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  </code></pre>
  
  <p><strong>Actual Request Paylod:</strong>  </p>
  
  <pre><code>------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  Content-Disposition: form-data; name="file"; filename="aFileName.zip"
  Content-Type: application/zip
  
  
  ------WebKitFormBoundaryysdTGvf0cRZVGpQ4
  </code></pre>