[TASK] Create credit note operation helpers - Credit Note and Refund Workflow

[africanitem]

Task Details

Epic: #551 [EPIC] Credit Note and Refund Workflow E2E Tests

Dependencies

• Depends on: Epic [EPIC] Prerequisites and Test Data Setup Workflow E2E Tests #489
• Depends on: Epic [EPIC] Invoice-to-Payment Workflow E2E Tests #512

Success Criteria

• Helper functions in e2e/helpers/credit-note-helpers.ts using pattern: CN-${Date.now()}