Fixes: #3061, #3489
* Fixed the flaky failure in rspec for super admin user controller due to unescaped user name check
- Show errors on login page - Dashboard for admin panel
* Feature: Introduce Super Admins - added new devise model for super user - added administrate gem - sample dashboards for users and accounts Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>