Feat/webpack (#2998)

* First commit

* Removed govuk for webpack. Modernized javascript importing. Removed dead js

* Fixed tests, a few styling bugs

* Fixed some table errors and regenerated backstop ref images

* Updated tests for coverage

* Changes from carlo suggestions

tests/javascripts/fileUpload.test.js

@@ -11,6 +11,7 @@ describe('File upload', () => {
 
   let form;
   let fileUpload;
+  let uploadControl;
 
   beforeEach(() => {