refactor: Reduce bundle size (#1575)

* async load cornerstoneWADOImageLoader chunk

* Lazy initializing of CornerstoneWADIImageLoader - delayed till Viewer creation

* Async loading of react-vtkjs-viewport

* withCornerstone HOC to wrap routes requiring CornerstoneWADOImageLoader initiazation

* removed dead code in comments

* initWeWorkers is no more. Remove al its references.

Co-authored-by: kedar.netelixir <kedar.choudhary@netelixir.com>
Co-authored-by: Danny Brown <danny.ri.brown@gmail.com>

platform/viewer/src/utils/initWebWorkers.test.js

@@ -1,23 +0,0 @@
-import initWebWorkers from './initWebWorkers.js';
-import cornerstoneWADOImageLoader from 'cornerstone-wado-image-loader';
-
-describe('initWebWorkers', () => {
-  it("initializes cornerstoneWADOImageLoader's web workers", () => {
-    initWebWorkers();
-
-    expect(
-      cornerstoneWADOImageLoader.webWorkerManager.initialize
-    ).toHaveBeenCalled();
-  });
-});
-
-describe('initWebWorkers', () => {
-  it("initializes cornerstoneWADOImageLoader's web workers only once", () => {
-    initWebWorkers();
-    initWebWorkers();
-
-    expect(
-      cornerstoneWADOImageLoader.webWorkerManager.initialize
-    ).toHaveBeenCalledTimes(1);
-  });
-});