feat: configuration to hook into XHR Error handling

* Error handling.

* Fix error handling, add redirect example.

* remove debugger

* docs: whitelabeling and httpErrorHandler

* bump dicomweb-client version

* bump cornerstone-wado-image-loader version

* Add more documentation around httpErrorHandler callback

* test: add errorHandler as an expected top level export

Co-authored-by: dannyrb <danny.ri.brown@gmail.com>

docs/latest/viewer/configuration.md

@@ -11,6 +11,14 @@ are:
 ```js
 window.config = {
   routerBasename: '/',
+  /**
+   * "White Labeling" is used to change the branding, look, and feel of the OHIF
+   * Viewer. These settings, and the color variables that are used by our components,
+   * are the easiest way to rebrand the application.
+   *
+   * More extensive changes are made possible through swapping out the UI library,
+   * Viewer project, or extensions.
+   */
   whiteLabeling: {
     /* Optional: Should return a React component to be rendered in the "Logo" section of the application's Top Navigation bar */
     createLogoComponentFn: function(React) {
@@ -30,6 +38,32 @@ window.config = {
       });
     },
   },
+  /**
+   * Internally, the OHIF Viewer fetches data primarily with the
+   * `cornerstoneWADOImageLoader` and the `DICOMWebClient`. If either of these
+   * receive a non-200 response, this method allows you to handle that error.
+   *
+   * Common use cases include:
+   * - Showing a notification with the UINotificationService
+   * - Redirecting the user
+   * - Refreshing an auth token
+   *
+   * @param {Object} error - JS new Error()
+   * @param {XMLHttpRequest} error.request - The XHR request that's onreadystate change triggered this callback
+   * @param {string} error.response - The XHR's response property
+   * @param {number} error.status - The XHR's status property
+   */
+  httpErrorHandler: error => {
+    const { request: xhr, response, status } = err;
+    const { responseType, statusText } = xhr;
+
+    // In local files, status is 0 upon success in Firefox
+    if (xhr.readyState === XMLHttpRequest.DONE) {
+      console.log(statusText, response, responseType);
+    } else {
+      console.warn('Likely CORS error');
+    }
+  },
   extensions: [],
   showStudyList: true,
   filterQueryParam: false,