[Ubercart D6] Migrate product translations

Postponed on #2897114: Products migrated to both nodes and products →

Problem/Motivation

The test fixture needs to be multilingual. Once translations are in the fixtures, we need to solve the following:

I have successfully migrated orders + products + order products. I don't have variations/attributes in my D6 use case. After import I modify a product variation and it gives me this error: "The SKU "birthday sea experience" is already in use and must be unique.". This is because migrate has migrated the English and Spanish nodes from D6 as two separate product variations in D8, both marked as English

See image attached. This is a query in the database for other variations with the same SKU. As you can see, its the same product, translated, but imported as 2 separate products.

I have come across this issue with migrate with normal nodes. Not sure if this is therefore migrate or commerce_migrate.

Proposed resolution

Add translations
Fix Product migrations ending up in 2 entities: Products migrated to both nodes and products →
Import product variation language properly and do not import the products to two different NIDs
Also apply the same to product_kits

Remaining tasks

Do it.
Make patch
..

User interface changes

N/A

API changes

N/A

Data model changes

N/A