fix: apply posting date sorting to invoices in Payment Reconciliation similar to payments

[UmakanthKaspa]

Summary

In the Payment Reconciliation tool, payment entries are ordered by their posting date, but the invoice entries were not.
This update adds sorting for invoice entries by their posting date in the get_invoice_entries function. The sorting of invoices is now aligned with the sorting applied to payments, ensuring consistency and improving the reconciliation process.

Changes

Updated get_invoice_entries function to sort non_reconciled_invoices by posting_date, similar to the sorting applied in get_nonreconciled_payment_entries to sort payments.

Screenshots

Before Sorting

After Sorting