[FIX] sale_stock: new product uom is done twice in sale order line on change - opw 607150
[FIX] sale_stock: comparing stock and sale order line qty is always done with default uom rounding precision
[FIX] sale_stock: error message does not match chosen units when not enough stock.
[FIX] sale_stock: when checkign the available quantity, do not include uom as it is already present in the context and will be included in the computation of product_obj.virtual_available (opw 607150)

fixing error message that does not match chosen units when not enough stock