chore: use standart output format of ESM

Author: waitingsong

framework-ts/yadan/index.ts

@@ -1,13 +1,16 @@
-import * as egg from 'egg'
+import { BaseContextClass, Controller, EggApplication, Service } from 'egg'
 
 import Agent from './lib/agent'
 import Application from './lib/application'
 import startCluster from './lib/cluster'
 
-const newEgg = {
-  ...egg,
+export {
   Agent,
   Application,
   startCluster,
+
+  BaseContextClass,
+  Controller,
+  EggApplication,
+  Service,
 }
-export = newEgg