Task: [#4890396](https://www.odoo.com/odoo/my-tasks/4890396)
Community PR: [#221924](https://github.com/odoo/odoo/pull/221924)

---
Improves the POS experience by allowing users to reopen and edit
configurable and combo products directly from their orderlines. When a
product is edited to match another existing line, the lines are
automatically merged to avoid duplicates.

- Introduced `useTimedPress` to support both click and long press
interactions.
- Reopening a configurator now pre-fills default attributes,
custom values, and combo selections.
- Removed click delay when selecting an orderline, improving
responsiveness.
- Extracted logic for configurator, combo choice, unit price
computation, and orderline merging from `addProductToOrder` into
dedicated functions (`tryMergeOrderline`, etc.) for reuse across
the codebase.

---

The Combo/Product Configurator popups no longer receive default
values directly.
Instead, they now work with the orderline passed as a prop.

** Combo Configurator Popup **
- Use `props.line.selectedComboIds` as the source for default values.
- Save the initial `state.combo` so it can be restored on discard.
- Add a **Discard** button in the popup footer.

** Product Configurator Popup **
- Use `props.line.selectedAttributes` for the default values.
- If there is no orderline like new combo item, fall back to
`props.comboItem?.saveStateAttributes`.
- Save the initial `state.selectedAttributes` so it can be restored on
discard.
- Expose `selectedAttributes` on `pos.orderline` as a function so it can
be recomputed at any time.

** Bug Fix: Price **
- Fixed a bug where updating a combo item directly from the Order
Summary used the wrong price (ignoring the combo).
- We now open the **Combo Configurator** instead of the
**Product Configurator** when editing a combo item from the Order
Summary.

---

When refreshing the page, we also lose the `free text` of the
`custom_attribute_value`.
By adding the model `product.attribute.custom.value` to the
`get databaseTable()` from `DataServiceOptions`, we ensure that the
records are saved in IndexedDB