Products: access to related/up-sell/cross-sell product fields

[misha-kotov]

Description

As a Magento developer, I want access to fields of related/up-sell/cross-sell products so I can fetch data for those secondary products in one call and render them on storefront.

Benefits

Developer productivity, request efficiency, being able to execute one call instead of several

Acceptance criteria

• GraphQL user can request the following fields for related/upsell/cross-sell product from original first-level products:
  • Name
  • SKU
  • Regular and minimal price (full object)
  • Main image
  • url key
  • canonical url
• Important: implementation should make use of deferred field resolution in interest of performance (see media gallery implementation as reference)

[naydav]

#371