Fix acceptance

* Fix acceptance info API to return user_id
* Adjust the url sent in the role / license acceptance email
  ```
  Change the url to <webview.url>/contents/<id>@draft/role-acceptance

  MANUAL-UPGRADE: Add "webview.url" to the ini file (e.g. development.ini)
  ```
Did we decide to take out the ``@draft`` for webview?