Feature/minor UI changes

[ashk6645]

This pull request refactors and enhances the Navbar component for improved code clarity, maintainability, and user experience. The main changes include optimizing the search functionality, improving accessibility and semantics, and cleaning up the code structure.

Functionality improvements:

• Refactored the search form to use useCallback for the handleSearch function, ensuring that the search query is trimmed and URL-encoded before navigating to the shop page. This prevents empty searches and improves reliability.
• Updated the cart count display by replacing a <button> with a more semantically appropriate <span>, improving accessibility and clarity.

Code style and structure:

• Improved code formatting throughout the component, including consistent indentation and splitting long lines for better readability. [1] [2]
• Enhanced JSX structure by properly formatting multi-line attributes and children, making the component easier to maintain. [1] [2]
• Ensured consistent export style by ending the file with export default Navbar; and adding a semicolon.