Enhancement [Frontend]: Add Logout Button for Mobile and Other Viewer Compatibility

I have observed that when viewing the site from mobile, tablet viewports, the logout button is not visible due to the responsive web design. This creates an issue where users on these devices do not have a way to log out. To improve the user experience a dedicated logout button that is accessible and visible on mobile and tablet viewports is necessary

https://github.com/Cloud-CV/EvalAI/assets/48647625/26dbb803-d7d4-4a6b-b56c-5fab8d5c59d2