title: rasa nlu fallback is returning intent instead of question
body: <p>I am using rasa (version 2) and with <a href="https://stackoverflow.com/questions/66558761/fall-back-policy-is-not-working-with-rasa-framework">this configuration</a> I have integrated the <code>FallbackClassifier</code>.</p>
  <p>But this returns the intent name instead of any question with yes and no button. And if i press yes, then it asks the question to user</p>
  <pre><code>Did you mean intent_name
  </code></pre>
  <p>this is how conversation went</p>
  <p><a href="https://i.stack.imgur.com/MBN4X.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MBN4X.png" alt="enter image description here" /></a></p>
  <p>Instead of showing intent_name it should show the question. Am i missing something?</p>
  <p>And on console</p>
  <pre><code>ERROR    rasa_sdk.endpoint  - No registered action found for 
  name 'action_default_fallback'.
  </code></pre>