[FEATURE] A way to do an action upon click release on a button

[Vermoot]

Description of the requested feature

I'm not sure whether this should be with the button or the eventbox widget, but it'd be nice to be able to set an action for when the user releases the click.

Proposed configuration syntax

(button :onclick "notify-send 'hello'" 
         :onclickrelease "notify-send 'world'"
)

Additional context

No response