Add suffix to resolve reference product mismatch

[olivercastro]

Summary of the issue
Products with custom options reflecting twice in Dibs Dashboard when creating an invoice.

Steps to reproduce

• Place an order with 2 products with distinct custom options (SKUs must be the same)
• Create a separate invoice for each products
• Check Dibs Dashboard

Expected Result

• Should only charge 2 items in DIBs dashboard

Actual Result

• Charged 2 items with 1 reserved item in DIBs dashboard

Reason:

• Incorrect usage of method getId. The getId method would return distinct values equivalent to their table values for
  \Magento\Sales\Model\Order\Invoice\Item = sales_invoice_item
  \Magento\Sales\Model\Order\Creditmemo\Item = sales_creditmemo_item
  \Magento\Sales\Model\Order\Item = sales_order_item

Always use quote_item_id