```
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
from_nested_type = from_type->getNestedType();
            to_nested_type = to_type->getNestedType();
            from_type = checkAndGetDataType<DataTypeArray>(from_nested_type.get());
            to_type = checkAndGetDataType<DataTypeArray>(to_nested_type.get());
        }
        
        if ((from_type == nullptr) != (to_type == nullptr))
            throw Exception{"CAST AS Array can only be performed between same-dimensional array types or from String",
                ErrorCodes::TYPE_MISMATCH};
        
        const auto nested_function = prepareUnpackDictionaries(from_nested_type, to_nested_type);
        return [nested_function, from_nested_type, to_nested_type](
                ColumnsWithTypeAndName & arguments, const DataTypePtr &, const ColumnNullable * nullable_source, size_t ) -> ColumnPtr
        {
            const auto & array_arg = arguments.front();
            if (const ColumnArray * col_array = checkAndGetColumn<ColumnArray>(array_arg.column.get()))
            {
                
                ColumnsWithTypeAndName nested_columns{{ col_array->getDataPtr(), from_nested_type, "" }};
                
                auto result_column = nested_function(nested_columns, to_nested_type, nullable_source, nested_columns.front().column->size());
                
                return ColumnArray::create(result_column, col_array->getOffsetsPtr());
            }
            else
                throw Exception{"Illegal column " + array_arg.column->getName() + " for function CAST AS Array", ErrorCodes::LOGICAL_ERROR};
        };
    }
    using ElementWrappers = std::vector<WrapperType>;
    ElementWrappers getElementWrappers(const DataTypes & from_element_types, const DataTypes & to_element_types) const