Documents that are only useful for demonstrations have been moved out of the standard Documents setup and into demo data. This keeps regular databases cleaner while preserving example content for demo environments.

Since https://github.com/odoo/enterprise/commit/f3c1cecf1583e0185d1bd75e757ce45b1912299a, some documents are added in Documents data. These documents are not meant to be installed on each databases, and only serve demonstration purposes. This commit therefore moves those documents data to demo data and reorder items in alphabetical order.

This update adjusts how several apps use database indexes to reduce unnecessary storage and improve search behavior where it matters. Helpdesk searches should better support partial text matching, while Knowledge, Marketing Automation, and Subscriptions avoid overly broad indexes that may slow maintenance without clear benefit.

See  odoo/odoo#135057 for the core ideas. This just applies them in locations triggering warnings.

This update aligns Belgian payroll accounting tests with a simplified leave duration setup. It reduces reliance on duplicate leave-related fields, helping keep payroll test maintenance simpler and more consistent.

Before this commit, there was way too much fields related to the duration of the leave in `hr_holidays`:
- number_of_days
- number_of_hours
- number_of_days_display
- number_of_hours_display
- number_of_hours_text
- duration_display

This commit only adapts the enterprise code to the change that only keeps `number_of_days`, `number_of_hours` and `duration_display` to simplify things.

Appraisal surveys now rely on a shared availability setting to decide when live session options should appear. This keeps appraisal survey screens cleaner and reduces duplicated customization, with no live sessions enabled for appraisals.

Where possible, use the newly introduced `session_available` field to identify whether to show options allows to reduce views overrides.

See related COM PR, where this field is an opt-in method based on survey_type, such that no live session is enabled for appraisals.

Task-2803327

The Documents app no longer shows the split PDF scissors button in the inspector when viewing documents from the Activity view. This avoids offering an action in a context where it should not be available, making the interface clearer for users managing activities.

Before this commit:
- Switch to the Activity view
- Schedule an activity for any PDF file and select it
- The scissor (split PDF) button is present on the inspector

After this commit:
- We remove the scissor (split PDF)  button from the inspector.

Task-3770691

The HR demo data has been adjusted so the Marc Demo manager account no longer receives extra access rights across related apps. Payroll conflict messages were also made clearer by showing the employee name, helping teams identify issues faster.

Expired or refused salary offers no longer show the salary configurator or send by email buttons. This helps prevent users from taking actions that are no longer relevant for inactive offers.

With this commit, when an offer is expired or refused, these buttons : "salary configurator" and "send by email" are hidden.

task : 3746557

Several payroll and project messages now use a shared formatting helper instead of manually building lists. This improves consistency and makes translated text read more naturally for users in different languages.

*=hr_payroll_account,project_enterprise,project_holidays

This PR replaces a few occurrences of list being manually constructed by making use of the new helper.

Task-3506960

Community: https://github.com/odoo/odoo/pull/154395