Always set payment_state to something on order finalize!

Stores who don't autocapture payments were not seeing anything on order
payment state probably because the order only had one payment with
pending state.

related to #4322
fix the pending spec with unscoped
MailMethod auth type names shouldn't be localized

It raises error when using the store in non-english locales. Ruby
Net::SMTP will call a method based on that string value

Fixes https://github.com/spree/spree_i18n/issues/367
Ensure only distinct products are returned at api/products#index

Fixes #4200
[api] Make products/index return unique products

It seems obvious in retrospect.