[DFC Products] Enable Variant Product mappings across DFC endpoints

[RaggedStaff]

We are enhancing DFC to include the ability to track Product > Variant relationships.

2 new relationships will be added to DefinedProduct : hasVariant (indicates the Product has a Variant with the given Id) & isVariantOf (indicates the Product is a Variant of the Product with the given Id).

Additional objects will be incorporated in a future version of the Ontology to enhance this further. Probably Variant as a subclass of DefinedProduct, details TBC. For now, we're just implementing these 2 relationships to hold this data.

Both Shopify & OFN support the concept of Product/Variants so hopefully this should be fairly seamless. We're not restricting anything from either Product or Variant at the moment, although we might want to look at the DFC issue for guidelines as to what to include/not include.

I'm thinking we need to amend Product import & also export. WDYT @mkllnk ?

[mkllnk]

we need to amend Product import & also export.

Yes, the export doesn't include master products at the moment. The import needs to recognise master products.

We'll need the new attributes in the data model for the connector.