[IMP] l10n_ar: total amount in letters for MiPyMEs

According to the Argentinean law N° 27440, it is required for MiPyMEs
document types to show in the report the total amount in letters.

closes odoo/odoo#80669

X-original-commit: 9ae95a9a
Signed-off-by: William André (wan) <wan@odoo.com>