Remove invoice number from the invoice line number

Problem

When importing invoices FOLIO provides a report with all invoice line numbers. FOLIO presents the Vendor invoice number as the primary identifier but invoice lines include the FOLIO invoice number which confuses what invoice they are a part of. This is also a misleading discrepancy when working with the invoice in the invoices ui.

Example:
12345-1, 12345-2, ...
becomes:
1, 2, ...

Approach

Update logic of org.folio.rest.impl.InvoiceLineHelper#buildInvoiceLineNumber

Acceptance criteria:

Given the user has created an invoice
When adding an invoice line manually or via POL
Then the system will number invoice lines starting at 1 and increasing in sequential order
Eg. The first Invoice line added with have an invoice number of 1

• Unit tests are updated
• API tests are updated as needed.