Added 'purchaseOrderNumber' field to Quotes- and Order-related types

With the new purchaseOrderNumber field, Buyers are now able to track their purchase throughout the order creation process with their Purchase Order Number. To support B2B scenarios, this new field is also supported on all types related to Quotes.

Changes:

• [API] Added optional field purchaseOrderNumber to OrderFromCartDraft, OrderImportDraft, QuoteRequestDraft, QuoteRequest, StagedQuote, Quote, Order.
• [API] Added setPurchaseOrderNumber update action to Orders and Order Edits APIs.
• [API] Added PurchaseOrderNumberSet message.
• [GraphQL API] Changed the QuoteRequestDraft type:
  • Input field purchaseOrderNumber was added to QuoteRequestDraft type
• [GraphQL API] Changed the OrderCartCommand type:
  • Input field purchaseOrderNumber was added to OrderCartCommand type
• [GraphQL API] Changed the ImportOrderDraft type:
  • Input field purchaseOrderNumber was added to ImportOrderDraft type
• [GraphQL API] Changed the StagedOrderUpdateAction type:
  • Input field setPurchaseOrderNumber was added to StagedOrderUpdateAction type
• [GraphQL API] Changed the StagedQuote type:
  • Added the purchaseOrderNumber field to the StagedQuote type.
• [GraphQL API] Changed the OrderUpdateAction type:
  • Input field setPurchaseOrderNumber was added to OrderUpdateAction type
• [GraphQL API] Changed the Quote type:
  • Added the purchaseOrderNumber field to the Quote type.
• [GraphQL API] Changed the Order type:
  • Added the purchaseOrderNumber field to the Order type.
• [GraphQL API] Changed the QuoteRequest type:
  • Added the purchaseOrderNumber field to the QuoteRequest type.

The following changes were introduced in terms of GraphQL SDL:

extend type StagedQuote {
  purchaseOrderNumber: String
}

extend type Quote {
  purchaseOrderNumber: String
}

extend type Order {
  purchaseOrderNumber: String
}

extend type QuoteRequest {
  purchaseOrderNumber: String
}

extend input QuoteRequestDraft {
  purchaseOrderNumber: String
}

extend input OrderCartCommand {
  purchaseOrderNumber: String
}

extend input ImportOrderDraft {
  purchaseOrderNumber: String
}

extend input StagedOrderUpdateAction {
  setPurchaseOrderNumber: SetStagedOrderPurchaseOrderNumber
}

extend input OrderUpdateAction {
  setPurchaseOrderNumber: SetOrderPurchaseOrderNumber
}

type PurchaseOrderNumberSet implements MessagePayload & OrderMessagePayload {
  purchaseOrderNumber: String
  oldPurchaseOrderNumber: String
  type: String!
}

input SetOrderPurchaseOrderNumber {
  purchaseOrderNumber: String
}

input SetStagedOrderPurchaseOrderNumber {
  purchaseOrderNumber: String
}

type SetStagedOrderPurchaseOrderNumberOutput implements StagedOrderUpdateActionOutput {
  type: String!
  purchaseOrderNumber: String
}