Is your feature request related to a problem?

Improve the information displayed in the checkout when a product is without stock

From https://www.prestashop.com/forums/topic/1041442-nobody-can-figure-it-out-we-need-a-specialist/

Describe the solution you'd like

Display the combination from the product without stock.

Additional context

Which one is the product withou

A while ago, we converted API controller specs into requests specs, see #2052. But those specs still have references from their old "life" that we can clean a little bit with a small effort.

In fact, their filenames still have the _controller_ part, which makes no sense now. Eg. solidus/api/spec/requests/spree/api/addresses_controller_spec.rb

Also, they contain references to the previo

Is your feature request related to a problem? Please describe.
Currently, if the developer wants to register a new admin account, it doesn't let it do that because sendgrid API keys are needed. Remove this dependency for local, and switch to using an identical emailService which uses Nodemailer (Gmail option preferred) since Nodemailer is free. Maybe feature flag this property

**Describe

The package creation/splitting is heavily dependant on zones. Prevent deletion of the last available zone.