title: load wordpress wp_editor dynamically (ajax)
body: <p>This is an answer/solution rather than a question, still there maybe some bugs, even I tried on my dev env.</p>
  
  <p>I recently try to use wp_editor in widget/menu, after some search, I did not find a complete solution as I want.</p>
  
  <p>I would share my solution in below after I dig into wp's code by hours:</p>