[FIX] point_of_sale: also clone orderline price

Otherwise during e.g. bill splitting of an orderline which had it's
price overridden you end up with the original price again.

Fixes #17810
Closes #17811

addons/point_of_sale/static/src/js/models.js

@@ -1108,6 +1108,7 @@ exports.Orderline = Backbone.Model.extend({
         orderline.quantity = this.quantity;
         orderline.quantityStr = this.quantityStr;
         orderline.discount = this.discount;
+        orderline.price = this.price;
         orderline.type = this.type;
         orderline.selected = false;
         return orderline;