Implement Default Source Selection Algorithm "By Minimal Delivery Cost"

[vrann]

Per Source Selection Algorithms HLD

Algorithm steps:

Delivery to fulfill the order could be made from one or several (more than one) sources

1. Evaluate each source for one product delivery
2. Fulfill the order by minimal cost sources (result is sum of each value)
3. Recalculate Shipping cost based on previous step result. Obtained value is displayed for the customer.

Acceptance Criteria:

1. There is default implementation of the source selection interface via "By Minimal Delivery Cost" source selection algorithm