add function iconv like PHP

```php 
//$string = '➢ Isaque';
 var_dump(iconv('UTF-8','ISO-8859-1//IGNORE',pack('C*', ...[226, 158, 162, 73, 115, 97, 113, 117, 101])));  
//string(6) "Isaque"
```
https://www.php.net/manual/pt_BR/function.iconv.php
https://github.com/ashtuchkin/iconv-lite