include curaçao

[zesertebe]

Is your feature request related to a problem? Please describe.
Yes, the problem is the absence of Curazao in the list of countries supported by the intl_phone_number_input library. I'm developing an application using Flutter that targets an international audience, including users from Curazao. The current limitation restricts our ability to provide a seamless experience for users in Curazao, as they cannot select their country when entering their phone numbers.

Describe the solution you'd like
I would like Curazao to be added to the list of countries supported by the intl_phone_number_input library. This would involve including Curazao's country code (+599) and ensuring that phone number validation rules are properly implemented for this country. The addition of Curazao would make the library more comprehensive and beneficial for developers targeting users in that region.

Describe alternatives you've considered
As a temporary workaround, I'm considering implementing a custom input field exclusively for Curazao users, where they can manually enter their phone numbers. However, this approach is not ideal as it deviates from the standardized experience provided by the intl_phone_number_input library and could lead to validation inconsistencies.

Additional context
Curazao is an important market for our application, and the inclusion of this country in the intl_phone_number_input library would significantly enhance our ability to cater to our users there. Adding Curazao would not only benefit our project but also other developers who may be facing similar challenges. We appreciate your consideration of this feature request and look forward to the possibility of including Curazao in the library.