
**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)

{
    for (size_t index : indices)
    {
        shards_info.emplace_back(from.shards_info.at(index));
        if (!from.addresses_with_failover.empty())
            addresses_with_failover.emplace_back(from.addresses_with_failover.at(index));
    }
    initMisc();
}
const std::string & Cluster::ShardInfo::insertPathForInternalReplication(bool prefer_localhost_replica, bool use_compact_format) const
{
    if (!has_internal_replication)
        throw Exception("internal_replication is not set", ErrorCodes::LOGICAL_ERROR);
    const auto & paths = insert_path_for_internal_replication;
    if (!use_compact_format)
    {
        if (prefer_localhost_replica)
            return paths.prefer_localhost_replica;
        else
            return paths.no_prefer_localhost_replica;
    }
    else
    {
        if (prefer_localhost_replica)
            return paths.prefer_localhost_replica_compact;
        else
            return paths.no_prefer_localhost_replica_compact;
    }
}
bool Cluster::maybeCrossReplication() const