Description
-----------

This PR enhances the account_edi_ubl module to fully support Swedish national PEPPOL BIS Billing 3.0 validation rules (SE-R-001 to SE-R-013), which are mandated by SFTI and enforced by Peppol Authorities. These validations are critical to ensure invoice acceptance and compliance for Swedish suppliers.

Additionally, it fixes the export of two missing but required BIS3 fields:
- RequisitionDocumentReference (mapped from invoice.ref)
- OrderReference (mapped from invoice.invoice_origin)

It also adds the required "Godkänd för F-skatt" designation for Swedish suppliers using SellerTaxRegistrationID.

Technical details
-----------------

- Extended `_get_partner_party_tax_scheme_vals_list` to add "Godkänd för F-skatt" to the tax scheme for Swedish suppliers.
- Extended `_export_invoice_vals` to export requisition and order references.
- Added detailed constraints in `_invoice_constraints_peppol_en16931_ubl` to enforce Swedish VAT number structure, organization number format and length, tax scheme requirements, VAT rates, bank account formatting, PaymentMeansCode logic, and Luhn checksum validation.
- Minor refactoring of existing code for better readability and maintainability.

Impact
------

These changes ensure that invoices generated for Swedish companies conform to national and Peppol standards, reducing the risk of invoice rejection and facilitating smoother e-invoicing processes.

References
----------

- Swedish validation rules documentation: https://sfti.se/download/18.427140af179361c4e462cc34/1620641679827/Beskrivning%20av%20svenska%20valideringsregler%202018-11-12.pdf
- PEPPOL BIS Billing 3.0 national rules: https://docs.peppol.eu/poacc/billing/3.0/bis/#national_rules