Desperate: toggle message tray keybinding without gnome-shell

[Noah Cutler]

Going a bit nutty here, using i3 WM on top of Gnome, and am only able to
trigger message tray (i.e. notification menu) display via mouse click.

On Gnome IRC I was told that there are no keybinding hooks in the
notification-daemon code, therefore toggle show/hide message is not
possible without a mouse click.

And yet, I can mouse click the message tray icon itself to show/hide, so
there "must" be a way to simulate this mouse click event.

Sadly, "xprops" does not help in identifying the window class of any panel
icon clicked menu item, presumably since these menus are not X windows, but
javascript generated god knows what.

Thanks for any clues as to how to pull this off; otherwise, it's Dunst or
other vanilla events menu, which would be ridiculous, pull entire gnome
stack via default Fedora install and not be able to use notifications that
work perfectly fine on mouse click ;-(