feat: Introduce refund window to control if a refund is offered for a purchase

[facumenzella]

Motivation

We're giving more power to users by adding one setting in the dashboard. A default window can be added to show / hide the refund action in the Customer Center

Description

• RefundWindowDuration
• latestPurchaseDate added to PurchaseInformation
• Use clock to mock current time and test it
• Added doc to Clock forced by linter 🙃

Follow-up of #4776

[ajpallares]

Mostly OK, although there are some unnecessary @_spi(Internal) that should be removed. I don't think I should approve this one as I lack most of the context, but I've left some comments to improve this PR

[ajpallares]

Thanks for the changes! Looks good to me, but as I said before, I leave approval to someone with actual context about the logic behind these changes

[vegaro]

Is this missing.@_spi(Internal) ?

[facumenzella]

This needs to be public because it's part of

        public enum RefundWindowDuration: Equatable {
            case forever
            case duration(ISODuration)
        }

[tonidero]

Just a comment about the naming but looking good!

[ajpallares]

I think this file shouldn't be here. Some leftover from git

[facumenzella]

damn