feat(PDFBurner): support unstructured annotations and simplify processing

- Added `UnstructuredAnnotations` property to handle annotations without structured IDs
- Changed default `hasStructuredID` to `False`, set to `True` only after successful parsing
- Updated `AddInstantJSONAnnotationToPDF` to process annotations directly instead of grouping by receiver
- Simplified logic for reversing annotations and applying seal positioning

EnvelopeGenerator.Application/Common/Notifications/RemoveSignature/Handlers/RemoveHistoryHandler.cs

@@ -34,7 +34,7 @@ public class RemoveHistoryHandler : INotificationHandler<RemoveSignatureNotifica
         await _repo.DeleteAsync(hists 
             => hists
                 .Where(hist => hist.Envelope!.Uuid == notification.EnvelopeUuid)
-                .Where(hist => hist.Status == EnvelopeStatus.DocumentSigned)
-                , cancel);
+                .Where(hist => hist.Status == EnvelopeStatus.DocumentSigned),
+                cancel);
     }
 }