[FIX] l10n_it_edi: split name

Fields `Nome` and `Cognome` cannot be identical. However, Odoo has only
a single field for name. Therefore, we split the name based on the
assumption that the name is written as 'Name Surname'.

opw-2093035

closes odoo/odoo#40198

X-original-commit: 9e8b33d6
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>