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>

platform/core/src/errorHandler.js

@@ -0,0 +1,6 @@
+// These should be overridden by the implementation
+const errorHandler = {
+  getHTTPErrorHandler: () => null,
+};
+
+export default errorHandler;