```
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
Additions additions [[maybe_unused]] = Additions())
    {
        using ColVecTo = typename ToDataType::ColumnType;
        const DateLUTImpl * local_time_zone [[maybe_unused]] = nullptr;
        const DateLUTImpl * utc_time_zone [[maybe_unused]] = nullptr;
        
        if constexpr (std::is_same_v<ToDataType, DataTypeDateTime> || to_datetime64)
        {
            const auto result_type = removeNullable(res_type);
            
            if (const auto dt_col = checkAndGetDataType<ToDataType>(result_type.get()))
                local_time_zone = &dt_col->getTimeZone();
            else
            {
                local_time_zone = &extractTimeZoneFromFunctionArguments(arguments, 1, 0);
            }
            if constexpr (parsing_mode == ConvertFromStringParsingMode::BestEffort || parsing_mode == ConvertFromStringParsingMode::BestEffortUS)
                utc_time_zone = &DateLUT::instance("UTC");
        }
        const IColumn * col_from = arguments[0].column.get();
        const ColumnString * col_from_string = checkAndGetColumn<ColumnString>(col_from);
        const ColumnFixedString * col_from_fixed_string = checkAndGetColumn<ColumnFixedString>(col_from);
        if (std::is_same_v<FromDataType, DataTypeString> && !col_from_string)