This change reorganizes purchase order line preparation so it can be reused by approval-related purchasing flows without depending on stock operations. It should not change day-to-day behavior, but it makes the purchasing logic easier to share and maintain across Odoo modules.

**[MOV]** ***: _prepare_purchase_order_line**
> Move the method `_prepare_purchase_order_line` from 'stock.rule' to 'purchase.order.line'.
> The purpose is to reuse it in approvals_purchase.
> 
>task-2040710

This update simplifies and renames internal survey data structures to make them easier to maintain and extend. It also updates related recruitment and skills survey integrations, helping prepare the survey app for upcoming live interaction and survey-building improvements without changing the core user experience.

This update renames an internal message-posting option so its expected value is clearer to developers. It should not change day-to-day user workflows, but it helps reduce future implementation mistakes across several business apps.