Empty lists for assets, deferred revenue, and deferred expenses now show clearer guidance when there are no records to display. Deferred expenses also now include sample entries, making the experience more consistent with deferred revenue and easier for users to understand.

Reword the default message for when a tree
view is empty for assets, deferred revenue,
and deferred expense as well as their
respective models.

Also, enable the samples on deferred expenses,
to make it consistent with deferred revenue.

Task id #2592816

The subscription screen now hides the generate invoice action when the selected payment method would lead to an error, such as manual payment or sending after a successful payment. This prevents users from starting an invoice flow that cannot complete and reduces avoidable support issues.

This PR prevents users from getting an error after clicking on 'generate invoice' button.
The button is hidden if the payment method is either manual or send after succesful payment.

task-2535878

The marketing automation test suite was updated to align with recent shared testing tool changes in the broader Odoo platform. This is an internal quality improvement that helps ensure future mail and template behavior changes are validated consistently.

Various test tools have been updated in community. This commit updates
enterprise code accordingly.

Task ID-2377974
Community PR odoo/odoo# 61467
Enterprise PR odoo/enterprise# 14633
Upgrade PR odoo/upgrade# 1907