```
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
{
            
            const ColumnWithTypeAndName & scale_column = arguments[1];
            UInt32 scale = extractToDecimalScale(scale_column);
            if (to_datetime64 || scale != 0) 
            {
                if (!callOnIndexAndDataType<DataTypeDateTime64>(from_type->getTypeId(), call, ConvertDefaultBehaviorTag{}))
                    throw Exception("Illegal type " + arguments[0].type->getName() + " of argument of function " + getName(),
                                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
                return result_column;
            }
        }
        bool done;
        if constexpr (to_string_or_fixed_string)
        {
            done = callOnIndexAndDataType<ToDataType>(from_type->getTypeId(), call, ConvertDefaultBehaviorTag{});
        }
        else
        {
            
            
            if (to_nullable && WhichDataType(from_type).isStringOrFixedString())
                done = callOnIndexAndDataType<ToDataType>(from_type->getTypeId(), call, ConvertReturnNullOnErrorTag{});
            else
                done = callOnIndexAndDataType<ToDataType>(from_type->getTypeId(), call, ConvertDefaultBehaviorTag{});
        }
        if (!done)
        {
            
            if (std::is_same_v<ToDataType, DataTypeString>)