On checkout flow show sources where all cart products are available for pickup

[sidolov]

Description

All products can be picked up in one place if they are each assigned to the source the customer selects (even if they don’t have sufficient quantity there at the time of order).

Use case

1. Create two store pickup sources in the same region (both can be found according to In-Store Pickup radius setting).
2. Create product 1 and assign it to the first source.
3. Create product 1 and assign it to both sources.
4. Add both products to the shopping cart.
5. Proceed to checkout.
6. Choose "pick up in store" option.
7. Search for pickup locations

Expected result

Only the first source is available for the pick up since all products in cart assigned to it.

[sidolov]

Fixed in scope of #2839