[FIX] product: price precision
[FIX] product: price precision

- Set a decimal precision for 'Product Price' = 6
- Set a currency precision = 2
- In the product for view, set a 'Sales Price' = 0.123456

The price is rounded to 0.12, while one would expect it to be 0.123456.

We use the decimal precision of the field rather than the default
currency precision.

Fixes #21686
opw-800279

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo