fix(measurement and microscopy): various small fixes for measurement and microscopy side panel (#3696)

extensions/dicom-microscopy/src/components/MicroscopyPanel/MicroscopyPanel.tsx

@@ -76,8 +76,8 @@ function MicroscopyPanel(props: IMicroscopyPanelProps) {
   const { uiDialogService, displaySetService } = servicesManager.services;
 
   useEffect(() => {
-    const viewport = props.viewports[props.activeViewportId];
-    if (viewport.displaySetInstanceUIDs[0]) {
+    const viewport = props.viewports.get(props.activeViewportId);
+    if (viewport?.displaySetInstanceUIDs[0]) {
       const displaySet = displaySetService.getDisplaySetByUID(viewport.displaySetInstanceUIDs[0]);
       if (displaySet) {
         setStudyInstanceUID(displaySet.StudyInstanceUID);