## Issue:
When a Purchase Order is linked to a Project and its quantity is billed through multiple vendor bills, the "Expected" amount in the project profitability view was incorrect

## Cause:
When at least one invoice line exists for a PO line, `_get_profitability_items()` computes `to_bill` and `billed` amounts without using the purchase order's ordered quantity This causes the computation to only consider the quantities already billed, ignoring the remaining quantity that still needs to be billed: https://github.com/odoo/odoo/blob/cdb8370647ca4b07f89edaf5fcc687508f6af16d/addons/project_purchase/models/project_project.py#L155-L178

Additionally, the code included all credit notes, even those that were canceled

## Steps to reproduce:
- Ensure the "Sales" app is installed to display project profitability
- Create a new Project "Profitability" and mark it as Billable
- Create and confirm a PO (any product, quantity: 5, unit price: 100, Taxes: None, Other Information > Project: "Profitability")
- Check the project dashboard for Purchase Orders (Expected: -500, To Bill: 0, Billed: 0)
- Create and confirm a Vendor Bill (Quantity: 2)
- Check the project dashboard for Purchase Orders (Expected: -200, To Bill: 0, Billed: -200)
- Create and confirm a Vendor Bill linked to the PO using Auto-Complete (Quantity: 3)
- Check the project dashboard for Purchase Orders (Expected: -500, To Bill: 0, Billed: -500)

opw-5077609

Forward-Port-Of: odoo/odoo#229221

### Issue:

Due to this issue, in the project sharing, the customer preview doesn't reflect the actual behaviour of the portal view. It shows non-validated timesheets even if invoicing policy is validated timesheets only.

#### To reproduce:
1- Create a db with sale_project and sale_timesheet_enterprise
2- Configure invoicing policy to validated timesheets only
3- Create a service product:
- Create on Order: Project & Task
- Invoicing policy: Based on Timesheets

4- Create a Quotation for the product and confirm it
5- Open project from smart button
6- Share project with a portal user with Edit access
7- Open tasks, and add two timesheets to the task
8- Open timesheet app, and validate one of the timesheets
9- From project page, click on Customer preview
10- In preview, open the task. You can see both timesheets which is a different behaviour if you view the project using portal user. Using portal user, only validated timesheets are shown.

### Cause:

The timesheets are filtered here to only show validated timesheets:

https://github.com/odoo/enterprise/blob/8223ed0765c6064b88280656a5ab6b13ca9a431f/sale_timesheet_enterprise/models/project_task.py#L73-L91

However, it is filtered only if user is portal. In customer preview the user is still the internal user, as a result the timesheets will not be filtered.

To fix that we can check if project_sharing_id exist in context to filter timesheets.

opw-5093339