[17.0][ADD] stock_report_partner_ref: add customer reference to picking reports

[atgalvez08]

@BinhexTeam

This module extends stock picking reports to display the customer reference (partner.ref).

Motivation

In many logistics workflows, the partner reference is a key identifier used by customers, suppliers, and external systems (e.g. EDI or retail platforms).

Standard Odoo stock reports (delivery slip and picking operations) do not include this reference, which can complicate customer identification and require manual cross-checking during warehouse operations.

Features

• Adds the customer reference to:
  • Delivery Slip (stock.report_delivery_document)
  • Picking Operations (stock.report_picking)
• Uses a simple fallback logic:
  • picking.partner_id.ref
  • picking.partner_id.commercial_partner_id.ref

Design

• No changes to data models
• No impact on existing workflows
• Lightweight QWeb inheritance
• Logic kept intentionally minimal and aligned with standard Odoo behavior

Use cases

• EDI integrations requiring customer codes
• Retail and distribution environments
• Warehouses where customer reference is needed in printed documents

Future improvements

• Optional configuration to enable/disable display
• Extension to additional stock reports

[rrebollo]

Code Review: Great work! The code looks good to me (LGTM). Thank you for your contribution! I've provided a few suggestions for your consideration—feel free to address them as you see fit.

I think having the option to enable or disable this behavior at the stock.picking.type level would be a plus.