Migrate built-in extensions to use manifest-based activate hooks (#5435)

* Convert jQuery/IIFE wrappers to exported init() functions and register activate hooks in 8 extension manifests

* Convert remaining extensions to exported init() with activate hooks and await initExtensions()

- Convert jQuery/IIFE wrappers to exported init() functions in expressions, memory, quick-reply, regex, stable-diffusion, translate, tts, and vectors extensions

- Register init functions as activate hooks in extension manifests

- Properly await async initExtensions() in firstLoadInit()

* Fix eslint

---------

Co-authored-by: Cohee <18619528+Cohee1207@users.noreply.github.com>

public/scripts/extensions/expressions/index.js

@@ -2140,7 +2140,7 @@ function migrateSettings() {
     }
 }
 
-(async function () {
+export async function init() {
     function addExpressionImage() {
         const html = `
         <div id="expression-wrapper">
@@ -2511,4 +2511,4 @@ function migrateSettings() {
             </div>
         `,
     }));
-})();
+}