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/moduleRegistry.js

@@ -0,0 +1,40 @@
+const modules = new Map();
+
+export function registerModule(name, ModuleClass) {
+  modules.set(name, ModuleClass);
+  window.NotifyModules = window.NotifyModules || {};
+  window.NotifyModules[name] = ModuleClass;
+}
+
+export function initModules() {
+  const moduleElements = document.querySelectorAll('[data-module]');
+
+  moduleElements.forEach(element => {
+    const moduleName = element.getAttribute('data-module');
+    const moduleStarted = element.getAttribute('data-module-started');
+
+    if (moduleStarted) return;
+
+    const ModuleClass = modules.get(moduleName);
+
+    if (!ModuleClass) {
+      console.warn(`Module "${moduleName}" not found in registry`);
+      return;
+    }
+
+    try {
+      const moduleInstance = new ModuleClass();
+
+      if (moduleInstance.start && typeof moduleInstance.start === 'function') {
+        moduleInstance.start(element);
+      }
+
+      element.setAttribute('data-module-started', 'true');
+    } catch (error) {
+      console.error(`Error initializing module "${moduleName}":`, error);
+    }
+  });
+}
+
+window.NotifyModules = window.NotifyModules || {};
+window.NotifyModules.start = initModules;