Add option to reverse order of columns

[brad-decker]

Thanks for all the work on the studio product. With recent changes, I was able to eliminate the need to use a custom layout component for 90% of my use cases. The one thing I still use it for is when I have a column setup where the order of the columns should change in different break points. The common use case I have is for a row of columns where each row alternates image on left, content on right then image on right, content on left, while in a desktop breakpoint. On Mobile it has to go image, content, image, content, image, content which would only work if the column order could be reversed.