
**Bug description**
Unlike `cluster()`, `clusterAllReplicas()` does not implement `_shard_num`. 

I would expect
```
SELECT _shard_num
FROM clusterAllReplicas(prod, system.one)
ORDER BY _shard_num ASC
FORMAT PrettyCompactMonoBlock

┌─_shard_num─┐
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
│          0 │
└────────────┘
```
to have an output more useful like
```
SELECT _shard_num
FROM cluster(prod, system.one)
ORDER BY _shard_num ASC
FORMAT PrettyCompactMonoBlock

┌─_shard_num─┐
│          1 │
│          2 │
│          3 │
│          4 │
│          5 │
│          6 │
│          7 │
│          8 │
│          9 │
│         10 │
│         11 │
│         12 │
│         13 │
│         14 │
│         15 │
└────────────┘
```

**Releases where this has been tested**

* v20.3.12.112-stable

**References**

[cluster, clusterAllReplicas documentation](https://clickhouse.tech/docs/en/sql-reference/table-functions/cluster/)

[_shard_num documentation](https://clickhouse.tech/docs/en/engines/table-engines/special/distributed/#virtual-columns)

const Poco::Util::AbstractConfiguration & config,
        const String & config_prefix,
        const String & cluster_,
        const String & cluster_secret_,
        UInt32 shard_index_,
        UInt32 replica_index_)
    : cluster(cluster_)
    , cluster_secret(cluster_secret_)
    , shard_index(shard_index_)
    , replica_index(replica_index_)
{
    host_name = config.getString(config_prefix + ".host");
    port = static_cast<UInt16>(config.getInt(config_prefix + ".port"));
    if (config.has(config_prefix + ".user"))
        user_specified = true;
    user = config.getString(config_prefix + ".user", "default");
    password = config.getString(config_prefix + ".password", "");
    default_database = config.getString(config_prefix + ".default_database", "");
    secure = config.getBool(config_prefix + ".secure", false) ? Protocol::Secure::Enable : Protocol::Secure::Disable;
    compression = config.getBool(config_prefix + ".compression", true) ? Protocol::Compression::Enable : Protocol::Compression::Disable;
    priority = config.getInt(config_prefix + ".priority", 1);
    const char * port_type = secure == Protocol::Secure::Enable ? "tcp_port_secure" : "tcp_port";
    is_local = isLocal(config.getInt(port_type, 0));
}
Cluster::Address::Address(