use new list of countries and adapt backend and frontend to it

backend/app/plugins/wiaas/includes/api/class-wiaas-rest-user-api.php

@@ -9,7 +9,7 @@ class Wiass_REST_User_API {
 	private static $namespace = 'wiaas';
 
 	public function __construct() {
-		include_once dirname( __FILE__ ) . '/user/class-wiaas-user-profile.php';
+		include_once dirname( __FILE__ ) . '/../class-wiaas-countries.php';
 	}
 
 
@@ -43,7 +43,7 @@ class Wiass_REST_User_API {
 	}
 
 	public static function get_countries(){
-		$countries = Wiaas_User_Profile::get_list_of_countries();
+		$countries = Wiaas_Countries::get_list_of_countries();
 
 		return new WP_REST_Response($countries);
 	}