📈(backend) capture an event when a document is imported

We want to capture an event when a file is imported. We add in the
properties the type of file imported and if it is in the
create-for-owner api call.

src/backend/core/api/viewsets.py

@@ -755,6 +755,12 @@ class DocumentViewSet(
                 serializer.validated_data["content"] = converted_content
                 serializer.validated_data["title"] = uploaded_file.name
                 logger.info("conversion ended successfully")
+
+                posthog_capture(
+                    PosthogEventName.DOC_IMPORTED,
+                    self.request.user,
+                    {"content_type": uploaded_file.content_type},
+                )
             except ConversionError as err:
                 logger.error("could not convert file content with error: %s", err)
                 raise drf.exceptions.ValidationError(