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

app/assets/javascripts/index.js

@@ -0,0 +1,84 @@
+// Webpack Entry Point
+
+// Vendor libraries
+import $ from 'jquery';
+window.jQuery = window.$ = $;
+
+import './jquery-expose.js';
+import 'query-command-supported';
+import 'textarea-caret';
+import * as cbor from 'cbor-js';
+
+// D3 - selective imports for tree shaking
+import {
+  select,
+  scaleLinear,
+  scaleBand,
+  scaleSymlog,
+  scaleOrdinal,
+  axisBottom,
+  axisLeft,
+  stack,
+  stackOrderNone,
+  stackOffsetNone,
+  sum,
+  max,
+  format,
+  interpolate
+} from 'd3';
+
+window.CBOR = cbor;
+window.d3 = {
+  select,
+  scaleLinear,
+  scaleBand,
+  scaleSymlog,
+  scaleOrdinal,
+  axisBottom,
+  axisLeft,
+  stack,
+  stackOrderNone,
+  stackOffsetNone,
+  sum,
+  max,
+  format,
+  interpolate
+};
+
+window.NotifyModules = window.NotifyModules || {};
+
+// Core modules
+import './modules/init.js';
+import './modules/uswds-modules.js';
+import './modules/show-hide-content.js';
+import { registerModule, initModules } from './moduleRegistry.js';
+
+// Local modules
+import './radioSelect.js';
+import './liveSearch.js';
+import './preventDuplicateFormSubmissions.js';
+import { ErrorBanner } from './errorBanner.js';
+import './notifyModal.js';
+import './timeoutPopup.js';
+import { initCurrentYear } from './date.js';
+import './sidenav.js';
+import './validation.js';
+import './scrollPosition.js';
+
+initCurrentYear();
+
+// NotifyModules
+import './copyToClipboard.js';
+import './enhancedTextbox.js';
+import './fileUpload.js';
+import './errorTracking.js';
+import './templateFolderForm.js';
+import './collapsibleCheckboxes.js';
+import './radioSlider.js';
+import './updateStatus.js';
+import './main.js';
+import './listEntry.js';
+import './stick-to-window-when-scrolling.js';
+import './totalMessagesChart.js';
+import './activityChart.js';
+import './job-polling.js';