Use unicode emojis instead of flags

[muscal]

Hey there,

There is concern over opening up the CDN to retrieve the flag images. Can you replace the flags with unicode emojis so we don't have to use images.

This also seems like it would be a lot more scalable w/ less maintenance.

Thanks!

[goveo]

Hey, unfortunately, unicode flags don't display properly in all browsers, so I can't set them as the default.

[goveo]

@muscal Currently, you can avoid CDN usage by passing svg files for all countries to the flags prop.
https://react-international-phone.vercel.app/docs/Usage/CustomCountryFlags/