Change hotkey functionality so that "A" both selects AND executes the context menu item

[rfaile313]

The current functionality of the add-on works like this:

1. Right clicking any link in the browser adds the "🖇 A - Copy Link [A]ddress" menu item:

2. Pressing "A" with this context menu open highlights the menu item

But the user is still required to either click or press enter to actually execute the menu item and complete the process.

It would be nice if pressing "A" wherever this "🖇 A - Copy Link [A]ddress" menu item appears automatically copied the link without the additional click or enter key press.

[rfaile313]

Noting here that this seems specific to MacOS and works as expected on Windows 🤔