feat: cancel download

[adnanlah]

Hello,

I added a new IPC handler cancel-download to cancel the download completely, because closing the modal only doesn't stop the app from continuing the download in the background.

Thanks everyone for this project.

[RSS1102]

@adnanlah but, after canceling the update, another attempt to continue the update will result in the following error (without restarting the exe):
Cannot download differentially, fallback to full download: Error: cancelled
I haven't found the reason for this error yet.

[adnanlah]

Cannot download differentially, fallback to full download: Error: cancelled

True. I have fixed by generating a new CancellationToken after firing cancel(). It works fine for me now.

Thank you very much.

[RSS1102]

Cannot download differentially, fallback to full download: Error: cancelled

True. I have fixed by generating a new CancellationToken after firing cancel(). It works fine for me now.

Thank you very much.

After I performed the update cancel update-operation-update(repeated multiple timesupdate-operation), he still received an error. (Sorry, I don't quite understand this convenience. I'm not sure if it's due to operational issues. Have you ever had such a problem with your business?)

[ViniciusFXavier]

Suggested change

	} from 'electron-updater'
	import { CancellationToken } from 'electron-updater'
	CancellationToken
	} from 'electron-updater'