1. Introduce an option in restaurant config to allow setting tips after payment.
2. Tip form is shown in bills so the customers can choose/set their tips.
3. Validated orders are kept in TipScreen (access via TicketScreen) so that at the
end of the day, the user/cashier can set the tips for each validated order.
closesodoo/odoo#55488
Task-id: 2117029
Related: odoo/upgrade#1606
Signed-off-by: pimodoo <pimodoo@users.noreply.github.com>