This update clarifies the documentation for two key error codes, E8502 and E8505, within the Odoo testing tools. Specifically, it provides a clearer explanation of E8505 and includes an illustrative example to enhance understanding for users.

- Update documentation link for E8502.
- Clarify why E8505 is in place and give an example.

This update improves the 'Unpaid' filter in the vendor bill section, now including draft bills alongside posted bills. This allows users to see all outstanding bills, regardless of their status, leading to a clearer view of financial obligations. A technical adjustment ensures journal entries are properly filtered, maintaining data accuracy.

In this commit:
- Updated the `Unpaid` filter to show draft bills in addition to posted bills. The filter now includes all non-cancelled bills with payment status `Not Paid` or `Partially Paid`.
- Backported the logic from 18.0 to ensure journal entries are filtered out by checking that type is not equal to `journal_entry`.

task-5900283

Forward-Port-Of: odoo/odoo#247179