Subscription (#6069)

* subscription api

* subscription page

* subscriptionAPI.js

* buy quota

* add currency icons

---------

Co-authored-by: Michael An <2331806369@qq.com>

frontend/config/webpack.entry.js

@@ -38,6 +38,7 @@ const entryFiles = {
   sysAdmin: '/pages/sys-admin',
   search: '/pages/search',
   uploadLink: '/pages/upload-link',
+  subscription: '/subscription.js',
 };
 
 const getEntries = (isEnvDevelopment) => {