feat(data-modelling): Update Product.SecondHand component to use a custom component

[TravisAlmey]

The secondHand component of Product.Item uses canBeUsed and priceAdjustment fields denoting whether it is valid for an item to be a used product, and if so what the value of the product should be adjusted to be. These fields are currently independent, however it does not make sense for an item to have a price adjustment if the item should be be values as a used item.

Therefore the priceAdjustment field should only be enabled when the canBeUsed field is set to true.

• Change the secondHand component to be a custom component
• Link the canBeUsed and priceAdjustment fields to have a dependency
• Ensure the link from the Product.PriceAdjustment component to the product.item collection is maintained

Reference: #17 (comment)

[safwanyp]

Hey! Seems like a decent starting point for me. Can I take this up?
I will look into the steps and list them out, and maybe someone can make sure they're the correct steps to take 😄

[safwanyp]

Correct me if I'm wrong, but this looks like it's already done? I see a bunch of commits made right after the creation of this issue, that seem to do what is described here 👀