Old 4.3 code attached for a fork we had. Would need a lot of reworking.

Also for another +10h we can integrate with https://goshippo.com/ to provide live rate choices.

We'd need to add shopping catalogue fields for length, width and depth.

We'd need to implement taking of addresses locally, even if local payments isn't in use - and these would be passed through to the gateway.

The shipping cost could only be worked out after setting the address, so the cart flow would need tuning for that.

We'd have config options for Shippo, and if configured the shipping option management screen would allow you to add Shippo shipping options rather than just ones certain calculation parameters.

Even without Shippo, we should allow our shipping code to work out shipping using dimensions as a criteria.

I'm adding some TODOs in the code regarding this functionality.

Product prices have to be static in Composr, which includes shipping prices. HOWEVER, products are aggregated into orders, which have their own shipping price. At the order layer we can make it configurable as each order is implemented as it's own unique compound product.

Current limitations are being documented in the eCommerce tutorial....

Shipping:
- Shipping rates for shopping catalogue purchases may not vary based on shipping destination
- User-selectable shipping options are not supported
- Shipping costs for individual items are summed up, there's no shared base price
- Free shipping above a certain payment amount is not supported
- Product catalogue shipping may be calculated by weight, physical dimensions are not considered

Replaced with #3065 and #3066.