Convert same height & width to size utility

[fotrino]

This unifies the same height & width properties into size like h-4 w-4 -> size-4.
Also makes code more consistent, instead of having w-20 h-20 in one place and h-20 w-20 in other, just use size-20.
Finally instead of having sm:h-10 sm:w-10 you can just use sm:size-10.