This update improves how Odoo handles electronic payments for website sales, quotes, and customer invoices. Businesses can now choose whether online payments simply record a payment, confirm the sales order, or also create and pay the invoice automatically, reducing manual follow-up and payment mismatches.

Two main things implemented by this PR:
- Automatic handling of electronic payments through website_{sale,quote}. Provides three options that can be set on the payment acquirer:
  - do nothing
  - validate SO
  - validate SO, generate and pay invoice
- Pay invoices in the backend with a saved payment.token belonging to a customer through a new electronic account payment type.

Adds support for importing CAMT.053 bank statement files, a European SEPA format increasingly used by banks in countries such as Austria, Germany, and the Netherlands. This helps businesses process bank statements from more banks directly in Odoo and prepares for broader replacement of older MT940/942 formats.

… format Bank Statement

Support for importing CAMT file:
CAMT format is used in several countries in Europe as a format to import bank statement
camt is part of sepa and should replace MT940/942 electronic account  statements in europe. Banks in Austria already provide camt files, so do  banks in Germany and the Netherlands.

This update restores expense sheet handling and adds improvements to the employee expenses workflow. It helps businesses manage, approve, report, and pay employee expenses more effectively within Odoo.

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Website contract payments are aligned with the standard payment setup by relying on the shared payment acquirer configuration. The update also renames stored payment methods to payment tokens, making recurring contract payments clearer and more consistent across Odoo.

Enterprise part of https://github.com/odoo/odoo/pull/12394

The Mass Mailing module was reorganized and updated to Odoo's newer internal framework, making it easier to maintain and evolve. The change also ensures unsubscribe links are correctly added to outgoing campaign emails, supporting better compliance and recipient experience.

<b>TASK:<b> https://www.odoo.com/web#id=13385&view_type=form&model=project.task&action=327
<b>PAD:</b> https://pad.odoo.com/p/r.AAcxdoY19shFk0xW

Ross Golder has added the required contributor license agreement confirmation. This administrative update helps ensure future contributions can be reviewed and accepted under Odoo's contribution rules.

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