The official Ginger Payments and Kassa Compleet extensions for Magento 1.x pass the same customer data to «POST /v1/orders/» besides the «customer/locale» format

[dmitrii_fediuk]

• The official Kassa Compleet extension for Magento 1.x duplicates a customer-related code in 4 places.
• The official Ginger Payments extension for Magento 1.x duplicates a customer-related code in 5 places.
• [Kassa Compleet] What is the right format of a customer’s locale in a «POST /v1/orders/» request?.
• [Ginger Payments] The «customer/locale» property is absent in the JSON Schema of a «POST /v1/orders/» request, but is passed by the official extension for Magento 1.x.

The Ginger Payments extension passes a customer’s locale as nl.
The Kassa Compleet extension passes a customer’s locale as nl_NL.

Both formats are correct by the Kassa Compleet’s JSON Schema of a «POST /v1/orders/» request.