title: WSO2 Token generation without password
body: <p>We've requirement of generating access token without using user's password. User's email, client's id &amp; secret can be provided. This will be internally used within a specific client.</p>
  <p>What's the best way of fulfilling this requirement. Should be change the implementation in Password Grant Handler or Can have some implementation. If Custom grant type is implemented, We don't want it to be exposed in open-id configuration.</p>
  <p>WSO2 IS v5.10.0</p>