Added update action for the supply channel of Line Items in a Cart

You can now update the inventory supply channel for Line Items that are already in a Cart. Before, you could only achieve this via replacing the existing Line Item with a new one.

Changes:

• [API] Added Set LineItem SupplyChannel to Carts and My Carts.
• [GraphQL API] Added the following types to the GraphQL schema: SetCartLineItemSupplyChannel.
• [GraphQL API] Changed the CartUpdateAction type:
  • Input field setLineItemSupplyChannel was added to CartUpdateAction type
• [GraphQL API] Changed the MyCartUpdateAction type:
  • Input field setLineItemSupplyChannel was added to MyCartUpdateAction type

The following changes were introduced in terms of GraphQL SDL:

extend input CartUpdateAction {
  setLineItemSupplyChannel: SetCartLineItemSupplyChannel
}

extend input MyCartUpdateAction {
  setLineItemSupplyChannel: SetCartLineItemSupplyChannel
}

input SetCartLineItemSupplyChannel {
  lineItemId: String!
  supplyChannel: ResourceIdentifierInput
}