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/lib/localFileLoaders/pdfFileLoader.js

@@ -1,9 +1,10 @@
-import cornerstoneWADOImageLoader from 'cornerstone-wado-image-loader';
 import FileLoader from './fileLoader';
+import { getCornerstoneWADOImageLoader } from '../../utils/cornerstoneWADOImageLoader';
 
 const PDFFileLoader = new (class extends FileLoader {
   fileType = 'application/pdf';
-  loadFile(file, imageId) {
+  async loadFile(file, imageId) {
+    const cornerstoneWADOImageLoader = await getCornerstoneWADOImageLoader();
     return cornerstoneWADOImageLoader.wadouri.loadFileRequest(imageId);
   }