Improve audit traceability for custom product request audit messages

We implemented an improvement where the requestGUID will be included in the Elastic audit logging document for custom audit messages. This will make it possible to establish a clear relationship between a product request and its corresponding audit messages, improving traceability.

With this change, there will also be a clear distinction between custom audit messages related to a product request and those related to a Delegated Form submission. This will help ensure better filtering, reporting, and overall insight into audit data.