Currently to get an invoice attachment you need to make a call to the attachment endpiont for a specific entity id, then you need to make a call to the download end point for each found attachment.

We need an efficient way to be notified of weather there is an attachment or not, othewise we will quickly hit our api quote just looking up attachments on invoices.

Would be great if we could request all attachment details objects for an array of invoices to reduce the number of calls we need to make in order to find attachment details for invoices.