Implement `GM.xmlHttpRequest` upload property

[ACTCD]

• https://wiki.greasespot.net/GM.xmlHttpRequest
• https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/upload

Note

The fetch API still unable track upload progress, so it's interesting that this is instead easier to implement in XHR.

• https://fetch.spec.whatwg.org/#fetch-api
  The fetch() method is relatively low-level API for fetching resources. It covers slightly more ground than XMLHttpRequest, although it is currently lacking when it comes to request progression (not response progression).

[ACTCD]

https://wiki.greasespot.net/GM.xmlHttpRequest
upload - Object Optional. Object containing optional function callbacks (onabort, onerror, onload, onprogress) to monitor the upload of data. Each is passed one argument, the #Response Object.

I think our implementation may be incompatible with the original GM.
The original GM passes the same Response Object in the upload callbacks, but that makes no sense.

We will refer to the original XMLHttpRequestUpload API to pass non-inherited properties of theProgressEvent object.