[FIX] l10n_it_fatturapa_out: allow to write related_documents field belong to account.view_move_form when l10n_it_fatturapa_in is installed after l10n_it_fatturapa_out
[FIX] l10n_it_fatturapa_out: allow to write related_documents field belong to account.view_move_form when l10n_it_fatturapa_in is installed after l10n_it_fatturapa_out

This change fixes the following scenario:

- install l10n_it_fatturapa_out
- install l10n_it_fatturapa_in
- tick the flag *Enable electronic invoicing* on a partner
- create an invoice for the previous partner
- add some lines in Related Documents
- related documents are not saved

This is due to the order in which `account.view_move_form` inherited views are loaded (ref. https://github.com/odoo/odoo/blob/293f54336fe18b41579604a20969534006437460/odoo/addons/base/models/ir_ui_view.py#L595)

OCA/l10n-italy,dcorio/l10n-italy,OCA/l10n-italy,dcorio/l10n-italy,OCA/l10n-italy,dcorio/l10n-italy