fix: ellipse should use exponent (#2086)

* fix: prevent app from blowing up when snapshot modal is opened

* fix: use superscript tag to indicate ellipse is mm squared

* fix: update measurement item to allow us to specify html in MeasurementItem display text

extensions/cornerstone/src/CornerstoneViewportDownloadForm.js

@@ -13,7 +13,7 @@ const DEFAULT_SIZE = 512;
 const MAX_TEXTURE_SIZE = 10000;
 
 const CornerstoneViewportDownloadForm = ({ onClose, activeViewportIndex }) => {
-  const { enabledElement: activeEnabledElement } = getEnabledElement(
+  const { element: activeEnabledElement } = getEnabledElement(
     activeViewportIndex
   );