[Shopify] Fix wrong Refund Line ID being used

[onbuyuka]

Summary

This PR fixes a bug where the Shopify Connector was incorrectly using the Order Line ID instead of the actual Refund Line ID when creating refund line records. The issue caused incorrect data to be stored in the "Refund Line Id" field of the "Shpfy Refund Line" table.

Problem

When importing refund lines from Shopify, the system was extracting the lineItem.id from the GraphQL response and using it as both the "Refund Line Id" and "Order Line Id". This was incorrect because:

• lineItem.id represents the original order line item
• The actual refund line has its own unique ID that should be stored in "Refund Line Id"

Solution

1. Updated GraphQL queries to include the id field for refund line items:

   • ShpfyGQLRefundLines.Codeunit.al - Added id to the nodes selection
   • ShpfyGQLNextRefundLines.Codeunit.al - Added id to the nodes selection

2. Updated the refund line import logic in ShpfyRefundsAPI.Codeunit.al:

   • Now correctly extracts the refund line's own id for the "Refund Line Id" field
   • Uses lineItem.id only for the "Order Line Id" field (the reference to the original order line)

Work Item(s)

Fixes AB#617843