**Use case**
I'm using `ip_trie` on maxmind geoip databases. Given an IP address I want to find out what key was used (ie what network the IP comes under). But it seems it is not possible to look up the key field when using `dictGet`?

```
        <layout>
            <ip_trie/>
        </layout>
        <structure>
            <key>
                <attribute>
                    <name>network</name>
                    <type>String</type>
                </attribute>
            </key>
            <attribute>
                <name>geoname_id</name>
                <type>UInt32</type>
                <null_value>0</null_value>
            </attribute>
...
```

```
clickhouse :) select dictGet('geoip_city_blocks_ipv4', 'geoname_id', tuple(toUInt32(toIPv4('1.1.1.1')))) ;

┌─dictGet('geoip_city_blocks_ipv4', 'geoname_id', tuple(toUInt32(toIPv4('1.1.1.1'))))─┐
│                                                                             2077456 │
└─────────────────────────────────────────────────────────────────────────────────────┘

clickhouse :) select dictGet('geoip_city_blocks_ipv4', 'network', tuple(toUInt32(toIPv4('1.1.1.1')))) ;

Received exception from server (version 20.11.3):
Code: 36. DB::Exception: Received from localhost:9000. DB::Exception: No such attribute 'network': While processing dictGet('geoip_city_blocks_ipv4', 'network', tuple(toUInt32(toIPv4('1.1.1.1')))). 
```

auto addr = key_ip_column_ptr->getDataAt(i);
        UInt8 mask = key_mask_column.getElement(i);
        IPv6Subnet target{reinterpret_cast<const uint8_t *>(addr.data), mask};
        auto range = ext::range(0, row_idx.size());
        auto found_it = std::lower_bound(range.begin(), range.end(), target, comp_v6);
        if (likely(found_it != range.end() &&
            memequal16(getIPv6FromOffset(*ipv6_col, *found_it), target.addr) &&
            mask_column[*found_it] == mask))
            set_value(i, static_cast<OutputType>(vec[row_idx[*found_it]]));
        else
            set_value(i, get_default(i));
    }
}
template <typename AttributeType, typename OutputType, typename ValueSetter, typename DefaultGetter>
void IPAddressDictionary::getItemsImpl(
    const Attribute & attribute, const Columns & key_columns, ValueSetter && set_value, DefaultGetter && get_default) const
{
    const auto first_column = key_columns.front();
    const auto rows = first_column->size();
    
    if (unlikely(key_columns.size() == 2))
    {
        getItemsByTwoKeyColumnsImpl<AttributeType, OutputType>(
            attribute, key_columns, std::forward<ValueSetter>(set_value), std::forward<DefaultGetter>(get_default));
        query_count.fetch_add(rows, std::memory_order_relaxed);
        return;
    }
    auto & vec = std::get<ContainerType<AttributeType>>(attribute.maps);
    if (first_column->isNumeric())
    {