[18.0][ADD] sale_stock_put_to_order: put-to-order zone configuration and target resolution

[StephaneMangin]

Configure locations as put-to-order zones to direct incoming goods to bins that already hold products from the same order.

Features of this module:

• Recursive is_pto boolean on stock.location (parent → children)
• Sale-order-aware product scope for bin selection
• Optional auto-select mode via _apply_putaway_strategy
• Storage-category validation on candidate bins
• Main extension entrypoints: _is_pto_location_valid, _get_pto_source_products, _prepare_pto_bin_group_vals

Supervised coding using Copilot AI with Claude Opus 4.6. Here are the different phases:

• customer need analysis
• reusable modules analysis (including integration efforts regarding initial budget)
• module creation and human testing
• Tests generation
• Optimisations (module architecture and extensibility, speed tests, etc)

Easily integrable with the enterprise module stock_barcode to help pickers select the proper bin as quickly as possible (during a pre-pack action for instance)