[Enhancement] Add a Reference of Original Accounting Estimate in Converted Invoices

[anuj-ever]

Issue:

Currently, when an accounting estimate is converted to an accounting invoice, there is no reference back to the original estimate. This makes it difficult for users to trace the payment back to its initial proposal, leading to potential confusion and incomplete audit trails.

Expected Condition:

When an accounting estimate is converted to an accounting invoice, there should be a clear reference back to the original accounting estimate. This will enable users to trace payments effectively and understand the transaction history, ensuring comprehensive documentation and improved financial tracking.

Supporting Document:

[samuelmbabhazi]

@anuj-ever
can we have clear expectations for this please !

cc: @evereq

[anuj-ever]

@samuelmbabhazi As a user, if we can save the original accounting estimate number/reference, when an accounting estimate is converted to an accounting invoice.

When converting a accounting estimate to an accounting invoice, the system should automatically save the original estimate number/reference in the invoice. This can be done through custom fields or database modifications. The user interface should auto-fill the estimate reference number in the invoice form, and reporting should link estimates to corresponding invoices for better traceability and accountability.

Similar behavior that is needed for sales estimate - #8524 (comment)