feat: surpoort GM.xmlHttpRequest upload property

[ACTCD]

resolve #807

[Copilot]

Pull Request Overview

This PR adds support for the upload property on GM.xmlHttpRequest by introducing new logic to process upload event handlers, updating the corresponding content script, API processing, background communication, and documentation.

• Update extraction of method names in userscripts entry point
• Incorporate upload handler processing and forwarding in the API and background scripts
• Update README with new API type definitions for upload events

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

File	Description
src/ext/content-scripts/entry-userscripts.js	Adjusted method extraction for GM. requests
src/ext/content-scripts/api.js	Added processing for upload event handlers
src/ext/background/main.js	Added upload event listener handling
README.md	Updated API docs for upload events

Comments suppressed due to low confidence (1)

src/ext/content-scripts/api.js:348

• [nitpick] The variable name 'XHRUploadHHandlers' is ambiguous. Consider renaming it to 'XHRUploadHandlers' for improved clarity.

const XHRUploadHHandlers = [