```
SELECT
    CAST(([2, 1, 1023], ['', '']), 'Map(UInt8, String)') AS map,
    map[10]
```

Triggers `Assertion 'n < size()' failed` in `DB::ColumnString::operator[](unsigned long)`
https://clickhouse-test-reports.s3.yandex.net/18481/64c4ade5b0e0c9a13d6c2475431daf431fc97554/fuzzer/fuzzer.log

Introduced here: #17829
First found here: #18481
{
                            bool convert_result = accurate::convertNumeric(vec_from[i], vec_to[i]);
                            if (!convert_result)
                            {
                                if (std::is_same_v<Additions, AccurateOrNullConvertStrategyAdditions>)
                                {
                                    (*vec_null_map_to)[i] = true;
                                }
                                else
                                {
                                    throw Exception(
                                        "Value in column " + named_from.column->getName() + " cannot be safely converted into type "
                                            + result_type->getName(),
                                        ErrorCodes::CANNOT_CONVERT_TYPE);
                                }
                            }
                        }
                        else
                        {
                            vec_to[i] = static_cast<ToFieldType>(vec_from[i]);
                        }
                    }
                }
            }
            if constexpr (std::is_same_v<Additions, AccurateOrNullConvertStrategyAdditions>)
                return ColumnNullable::create(std::move(col_to), std::move(col_null_map_to));
            else
                return col_to;
        }
        else