[FIX] Stock_Picking_invoicing: ACL if user doesnt have account group.

[joshkreud]

PR Content

This fixes an ACL error when trying to open a picking with attached invoices, when the user doesnt have rights to read the invoices.

Apparently Odoo still tries to read the field, even though the parent page already had groups=account.group_account_invoice.

Trivia

Yesterday I thought this issue lies in upstream in stock_picking_invoice_link. But upon further testing, I realized, that the read call that prompts the ACL error, is issued by the invoice_ids subtree in this module.