[FEAT] keyboard shortcuts on the pop-up dialog

[huyz]

When prompted whether to upload or paste locally, it would be nice to have keyboard shortcuts to pick the right options, maybe L for "Paste Locally" and U for "Upload".

Btw, it doesn't make sense to me for "Always Upload" to be the default option since that's something you would only do once.
The default option should be one that you would do repetitively. I would prefer that "Paste Locally" be the default option, but I guess you could argue that most people would want to "Upload" more often.