5010 redesign product form

Another case for Deface. 

Dimensions don't have any units, and I suspect that adding them in with Deface would be a common thing to do (if it isn't it should be). So really these need to be kept separate and have data-hooks added to them.

I do need to review this though, because it doesn't work on the front end – if there are no dimensions you get "h x w x d" with no numbers.