Implemented frontend for login and register routes

[shivam7147]

Description

Implemented authentication functionality for Collab Canvas.

• Integrated login and register forms in the frontend with proper validation.
• Configured token-based authentication using localStorage.
• Added login/logout buttons in the Canvas page with conditional rendering.
• Ensured proper redirects after login and registration.
• Displayed toast notifications for successful actions and errors (e.g., invalid credentials).

Semver Changes

• Patch (bug fix, no new features)
• Minor (new features, no breaking changes)
• Major (breaking changes)

Issues

Closes #24 - Implement frontend for login/register

Checklist

• I have read the Contributing Guidelines.
• Code has been tested locally.
• Proper error handling and notifications added.
• Frontend is responsive and visually appealing.