CIWEMB-295: Allow user to create credit note refund

[olayiwola-compucorp]

Overview

This PR adds the functionality that allows an admin user to record a cash refund for a credit note.

Before

The functionality doesn't exist

After

Technical Details

When a credit note cash refund is made, the following records are created during the reversal process:

• financial_trxn: A record of the refund payment.
• entity_financial_trxn for credit note: Links the credit note with the financial_trxn.
• entity_financial_trxn for credit note line: Each credit note line item is linked to the financial transaction, and the refunded amount is proportionally distributed among the credit note line items.