Support separate keydown/keyup event for hotkey about global-hotkey

[amrbashir]

@morajabi thanks for looking into this, the API should be straight forward, you would need to just add a field in GlobalHotKeyEvent

pub enum HotKeyState {
	Pressed,
	Released,
}

pub struct GlobalHotKeyEvent {
    /// Id of the associated [`HotKey`]
    pub id: u32,
	pub state: HotKeyState,
}

[morajabi]

I see in the macOS ffi impl we have kEventHotKeyPressed. Is there a reason kEventHotKeyReleased wouldn't work?
(I've seen it used in the wild: https://github.com/cocoabits/MASShortcut/pull/114/files#diff-bd9e25dca147d4385ffb9cc5e3766ae2051e1532203cebc902777a27a880e02fR21)

It is useful for creating a "hold to talk" interaction for our users. Happy to make a PR for macOS if the API is decided upon.

[amrbashir]

I think this maybe be possible on Linux(X11) and maybe Windows too (I have an idea but haven't tested it yet).

As for macOS, I see in the article that they are using private APIs which will result in your app getting rejected by The App Store so we can't use that. Since I am not a macOS dev, I will have to leave it to someone else to contribute.

[Megamannen]

+1 on this