feat(extgen): add support for callable in parameters

[alexandre-daubois]

Draft!

Depends on php#1724

// export_php:function my_array_map(array $data, callable $callback): array
func my_array_map(arr *C.zval, callback *C.zval) unsafe.Pointer {
	goArr := frankenphp.GoArray(unsafe.Pointer(arr))
	result := &frankenphp.Array{}

	for i := uint32(0); i < goArr.Len(); i++ {
		key, value := goArr.At(i)

		callbackResult := frankenphp.CallPHPCallable(unsafe.Pointer(callback), []interface{}{value})

		if key.Type == frankenphp.PHPIntKey {
			result.SetInt(key.Int, callbackResult)
		} else {
			result.SetString(key.Str, callbackResult)
		}
	}

	return frankenphp.PHPArray(result)
}

$strArray = ['a' => 'hello', 'b' => 'world', 'c' => 'php'];
var_dump(my_array_map($strArray, 'strtoupper'));

$arr = [1, 2, 3, 4, [5, 6]];
var_dump(my_array_map($arr, function($item) {
    if (is_array($item)) {
        return my_array_map($item, function($subItem) {
            return $subItem * 2;
        });
    }

    return $item * 3;
}));

/*
Output:

array(3) {
  ["a"]=>
  string(5) "HELLO"
  ["b"]=>
  string(5) "WORLD"
  ["c"]=>
  string(3) "PHP"
}
array(5) {
  [0]=>
  int(3)
  [1]=>
  int(6)
  [2]=>
  int(9)
  [3]=>
  int(12)
  [4]=>
  array(2) {
    [0]=>
    int(10)
    [1]=>
    int(12)
  }
}
*/