> Description of the issue/feature this PR addresses:

When a task/helpdesk_ticket contains non-validated timesheets and we change the task's project/helpdesk_team, we want the timesheets to follow the new project of the task.
By doing that, the timesheets will follow the task's project and the SOL of those timesheets will be correctly based on the SOL set on the task linked.
Tests are added to test this behavior. 

> Current behavior before PR:

- When the project of a task/ticket gets modified, the timesheets associated to the task/ticket gets un-linked to the task/ticket no matter the validation status of the timesheets.

> Desired behavior after PR is merged:

When the user changes the project of a task/ticket with timesheets from the task/ticket form:
- If there is at least 1 non-validated timesheet and the new project has not the timesheets feature enabled, raise an warning message to user, and allow the changes
- Set the new project_id as the project of the non-validated timesheets
- Validated timesheets don't get any changes, and keep their original project.

[task-3669013](https://accounts.odoo.com/web#id=3669013&cids=1&menu_id=4720&action=333&active_id=4105&model=project.task&view_type=form)

community PR: https://github.com/odoo/odoo/pull/153281

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