Saleor: Checkout process improvements

[mad-anne]

During my work on PR #2206 I found out few things that may improve checkout process.

Going forward/back between steps

Although we can go back to shipping address step from choosing shipping method, we can't go back from summary step, where billing address is set. I think that passing between steps should be allowed.

Clearing cart

We can remove every single item from cart, but there is no button like Clear cart. It would be useful, when customer wants to cancel all cart lines at once.

[tomcio1205]

Hi everyone, I started to handle with that issue.

[NyanKiyoshi]

@maarcingebala what about "Going forward/back between steps"? We probably could go for something like that?

[maarcingebala]

I was thinking about something like that, but for now, the simple solution implemented by @tomcio1205 is enough. We can think of such steps in the new storefront that we are just starting to work on.