When product has wholesale price it should use it whenever possible

[Roy Bao]

Step to reproduce

1. Create a product with both retail and wholesale price (minimum order quantity > 1)
2. Go to create order page
3. Search for this product
4. increate quantity to the moq that matches wholesale price, notice the price is still using retail price

Expected behaviour is after the quantity go over the moq of wholesale price it should automatically switch to wholesale price, and if user decrease the quantity again then it should go back to retail price