Add country selection dropdown and display flags for mentor profiles

[Madhawa97]

Is your feature request related to a problem? Please describe.

The current system uses free text input for country, leading to inconsistencies and potential invalid entries. A standardized dropdown will ensure data consistency and enable proper flag display.

Describe the solution you'd like

Implement a feature to allow mentors to select their country of residence from a dropdown and display a corresponding flag on their profile.

• Add a country selection dropdown to the mentor profile edit form
• Implement a component to display country flags on mentor profiles
• Update mentor profile view to show the flag alongside other profile information
• Ensure responsive design and proper sizing of flags for different screen sizes
• Implement error handling for cases where flag images fail to load

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here

Suggestions for flag display

1. Use a third-party API that serves flag images based on country codes (e.g., https://flagcdn.com or https://flagpedia.net)
2. Use Unicode country code flags (emoji) which are supported by most modern browsers
3. Implement a local mapping of country codes to flag image files, stored in the application's static assets

[Akshaydotcom]

Hey! Can I work on this? @anjula-sack

[anjula-sack]

Go ahead. @Akshaydotcom You can get the countries using /countries endpoint