Part 2 of 3 for T7841: Revamp buttons on the bottom to solve various usability issues
Depends on D10283
Nobody can ever find Spectacle's Configure window because the menu item to invoke is hidden in the Save menu, oddly enough. Once D10283: (1/3) Remove unnecessary Discard/Quit button lands, there'll be room for another button. So, we move the "Configure..." item out of the Save menu and into its own button.