[REF] stock: small code refactoring
[FIX] stock: fixed wrongly removed line from previous commit
[REF] stock: small code refactoring
[REF] product refactoring: prices.history model renamed into product.price.history + passed 'date' as real parameter instead of contextual one in get_history_price() because it makes more sense.
[IMP] product: simplify legacy useless code