Refactor: Update ```header``` component for global usage

[thxforall]

Description

Refactor the header component to ensure it works seamlessly as a common component across the application #26.

Tasks

• Simplify and optimize header structure
• Update styles for better consistency and responsiveness
• Redesign and improve navigation (login, search, etc.)
• Enhance animations and transitions for a smoother user experience
• Add support for dynamic content

Reason

The current header component has inconsistencies in navigation (login, search) and lacks modern animations or transitions.

Additional Notes

Ensure compatibility with all existing pages and enhance the overall user experience with updated visuals and functionality.