Feature request: `Quit` option for system tray

[ajmeese7]

It would be nice if there was a "Quit" option on the system tray icon to easily close the application, so the current process that requires 4 clicks to quit could be avoided.

While not required, one possible additional part of this button would be a confirmation dialog to ensure that the user did not accidentally click the "Quit" button.

Ref: https://github.com/keybase/client/issues/3773#issuecomment-863308150