Add source_image field to insight serial

Author: raphael0202

robotoff/models.py

@@ -99,6 +99,7 @@ def serialize(self, full: bool = False) -> JSONType:
                 "type": self.type,
                 "barcode": self.barcode,
                 "countries": self.countries,
+                "source_image": self.source_image,
                 **self.data,
             }