Hub: UX for Product Variants needs work

[poppabear8883]

Right now, after adding a variant option we can not add a new option after, only new option values can be added.

Managing the Product Variants screen looks like:

Here, I think instead of a list of option values for a "single" option, we should in-fact have a list of options to manage (including an add option feature). Once clicking on an option to manage we should then be presented with the available values for said option.