Allow Reversion to BetterCanvas

Hi Devs!

I appreciate the attempts to make BetterCampus/BetterCanvas a more all-in-one tool for Canvas users, but frankly, I just needed something lightweight to re-theme my Canvas into dark mode. The new app is treading on the territory of bloatware and I think it would be very helpful to have toggles to disable the new sidebar tabs BetterCampus adds, as well as options to disable all of the new features that take up screen space.

Will be searching for alternatives in the meantime.