Increment challenge score when a product is ordered & paid

[Tirodem]

Following #108

When a order is done & paid, for each product in the cart, check if the product is whitelisted in a live Challenge (non-draft, beging date < current date < end date) :

• If challenge mode = money amount, add product amount (in SATs) to challenge current score
• If challenge mode = order quantity, add product ordered quantity to challenge current score

Note : when no product is whitelisted on a challenge, do that for every product.

[coyotte508]

Pr #118 introduces a onOrderPaid function that can be used: https://github.com/B2Bitcoin/B2BitcoinBootik/pull/118/files#diff-68e2d47d872b8e27c8f8a5ae4ccdb5409fe481e6c03a49b3c7f323530c1107c0R23

[Tirodem]

Tested ok ✔️