This function is meant to compute the quantity from one UoM to another UoM, the rounding method parameter is meant to be used in that context.

If both UoM are the same, it should use the usual HALF-UP rounding method.

Explanations regarding the bug occurring in the related ticket:
- The OCR was matching a purchase order for which one of the lines had a quantity of exactly 6.
- When this PO was matched and imported on the vendor bill, the quantity of the related invoice line was rounded to 6.00000000000001. Under normal circumstances, the value would have stayed at 6 after rounding, but because the OCR runs within the context of a `_disable_discount_precision`, this kind of rounding discrepancy is possible.
- The billed quantity is then computed based on the quantity on the invoice line, 6.00000000000001. As it is rounded upwards to the nearest two decimals places, the final value is 6.01 instead of the expected 6.

opw-[6113387](https://www.odoo.com/odoo/my-support-tasks/6113387)

**Steps to reproduce:**
* Install the **l10n_cz** module.
* Create a customer invoice for a Czech company.
* Print the invoice.

**Observed behavior:**
* The **Tax ID (DIČ)** is displayed **twice** in the invoice header in default layout.
* **VAT** is displayed **twice** in the invoice headed in folder layout.

**Cause:**
* The `registry_vat_external_layout` template adds `company.vat` to `company_address_list`.
* Base external layouts already include `company.vat` in the same list.
* This results in duplicated DIČ rendering.

**Fix:**
* Remove the redundant VAT `<li>` from `registry_vat_external_layout`.
* Keep only the Czech-specific **Company ID** (`company_registry`) entry, which is not provided by base layouts.

Before:
<img width="900" height="261" alt="image" src="https://github.com/user-attachments/assets/9b5b81aa-a79d-4c93-8109-3c97d79356f4" />

After:
<img width="804" height="221" alt="image" src="https://github.com/user-attachments/assets/4b62eddc-6117-4f52-a8fb-2b03812aad8b" />

opw-6125766

### Steps to reproduce:
- Download 'Sales', 'Project', 'Employees', and 'Timesheets' apps
- Create an employee and link them to a user that doesn't have any access rights except to 'Timesheets = User:own timesheets'
- In Sales, create a service with the following specifications:
    - 'Create on Order' is 'Project'
    - 'Invoicing Policy' is 'Based on Timesheets'
- Create a new quotation that requests this service and click 'Confirm'
- In 'Project' > 'Configuration' > 'Projects', choose the newly created project and add a line that has the new employee in the 'Invoicing' tab
- Log in as that employee and go to 'Timesheets'
- Create a new entry for the newly created project
- Click the project's name
> Access Error: You are not allowed to access 'Collaborators in project shared'
(project.collaborator) records.

### Cause of Issue:
This happens because the user doesn't have access rights to the 'Project' app, hence they don't have access to `collaborator_ids` which are retrieved here. https://github.com/odoo/odoo/blob/3dfb2849acd899ccbf4048f2a15dff3c74aed96d/addons/project/models/project_project.py#L1113-L1120

### Fix:
Since an access to the 'Projects' app isn't necessary to view a project assigned to you, `sudo()` is necessary for hr_timesheet users without project access rights.

opw-6074833