Frontend/Ojusvi/Created Global Notification System

[ojusvi]

• Created a reusable notification component for the Employer Panel
• Added support for success, error, warning, and information notifications
• Replaced page-specific alerts with the shared notification system
• Added appropriate notification messages for API responses and user actions

Testing

• Tested success notifications
• Tested error notifications
• Tested warning notifications
• Tested notification behaviour across the updated Employer Panel pages
• Verified notification styling and display behaviour