fix(hooks): fallback handling for core invocations of hooks.fire

+ .on() which is the same as .register()

public/src/modules/hooks.js

@@ -9,6 +9,7 @@ define('hooks', [], () => {
 		Hooks.loaded[hookName] = Hooks.loaded[hookName] || new Set();
 		Hooks.loaded[hookName].add(listener);
 	};
+	Hooks.on = Hooks.register;
 
 	Hooks.hasListeners = hookName => Hooks.loaded[hookName] && Hooks.loaded[hookName].length > 0;
 
@@ -19,6 +20,9 @@ define('hooks', [], () => {
 
 	const _fireActionHook = (hookName, data) => {
 		Hooks.loaded[hookName].forEach(listener => listener(data));
+
+		// Backwards compatibility (remove this when we eventually remove jQuery from NodeBB core)
+		$(window).trigger(hookName, data);
 	};
 
 	const _fireStaticHook = (hookName, data) => {

src/meta/js.js

@@ -64,6 +64,7 @@ JS.scripts = {
 
 		'public/src/modules/translator.js',
 		'public/src/modules/components.js',
+		'public/src/modules/hooks.js',
 		'public/src/modules/sort.js',
 		'public/src/modules/navigator.js',
 		'public/src/modules/topicSelect.js',