This module replaces the structured country/state origin fields from ``product_origin``
with a flexible free-text field that can be defined per supplier.

**Problem:**

The standard ``product_origin`` module provides structured fields (country + state) for
product origin. However, suppliers often use creative and varied formats to describe
product origin:

* "Valencia, Spain"
* "Huerta de Ana, Aragón"
* "Organic Farm - Northern Italy"
* "Local producer - Basque Country"
* "Fair Trade - Colombia"

These free-form descriptions don't fit into structured country/state fields.

**Solution:**

This module adds a translatable ``origin_text`` field to ``product.supplierinfo`` that:

* Allows free-form text to describe product origin
* Is stored per supplier (different suppliers may have different origin info)
* Is translatable (can be described differently in each language)
* Is automatically displayed on the product based on the main vendor
  (from ``product_main_seller`` module)

**Features:**

* Free-text ``Origin`` field in supplier info (Purchase tab of product)
* Computed ``Origin`` field in product form (shows main vendor's origin)
* Field is visible in product list view (optional column)
* Full translation support for multiple languages
* Compatible with existing supplier management workflows
