Added 'productSelections' to Store limits query in the GraphQL API

You can now view Product Selections limits for Stores in the GraphQL API.

Changes:

• [GraphQL API] Changed the StoreLimitsProjection type:
  • Added the productSelections field to the StoreLimitsProjection type.

The following changes were introduced in terms of GraphQL SDL:

extend type StoreLimitsProjection {
  productSelections: Limit!
}