account_payment_order: Set invoice payment_state when an order is uploaded

[TeoGoddet]

When a payment method is not set to automatically post the payment lines on file upload, it would be great to have the invoice payment state set to 'in_payment' so that there is no double upload while the bank is processing the file.

Seems https://github.com/odoo/odoo/blob/013efbdfbf6bd6513a0c834ad61b807c780c5e5d/addons/account/models/account_move.py#L1239 and maybe https://github.com/odoo/odoo/blob/013efbdfbf6bd6513a0c834ad61b807c780c5e5d/addons/account/models/account_move.py#L2163

Otherwise this could be overrided globally https://github.com/odoo/odoo/blob/013efbdfbf6bd6513a0c834ad61b807c780c5e5d/addons/account/models/account_move.py#L1260

Would such feature be interesting ? I could work on this this summer.

Should it be in account_payment_order or in a dedicated module extending account_payment_order ?