[FIX] account_edi_ubl_cii: add italian EAS code for peppol Bis 3

Currently, it's not possible to check the 'Peppol Bis 3' option on the
journals of Italian companies, since Italy is not present in our mapping
`COUNTRY_EAS`.

The EAS for Italian companies may be the codice fiscal (code: 0210) or
the VAT number (code: 0211). See
https://peppol.agid.gov.it/en/news/expiration-validity-codes/



Use the VAT number by default, and add it in our mapping such that the
option now appears for Italian companies.

opw-3346572

closes odoo/odoo#126168

Signed-off-by: Florian Gilbert (flg) <flg@odoo.com>