解决一些语法错误

src/components/measures/DARAMeasurementTool.ts

@@ -296,10 +296,10 @@ export default class DARAMeasurementTool extends AnnotationTool {
         textBoxRight: annotation.data.handles.textBoxRight,
       },
       metadata: {
-        viewPlaneNormal: annotation.metadata.viewPlaneNormal || [0, 0, 1],
-        viewUp: annotation.metadata.viewUp || [0, 1, 0],
-        FrameOfReferenceUID: annotation.metadata.FrameOfReferenceUID || '',
-        referencedImageId: annotation.metadata.referencedImageId || '',
+        viewPlaneNormal: annotation.metadata?.viewPlaneNormal || [0, 0, 1],
+        viewUp: annotation.metadata?.viewUp || [0, 1, 0],
+        FrameOfReferenceUID: annotation.metadata?.FrameOfReferenceUID || '',
+        referencedImageId: annotation.metadata?.referencedImageId || '',
       },
     };
   }