
**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)

{
    auto pos = host_port_string.find_last_of(':');
    if (pos == std::string::npos)
        throw Exception("Incorrect <host>:<port> format " + host_port_string, ErrorCodes::SYNTAX_ERROR);
    return {unescapeForFileName(host_port_string.substr(0, pos)), parse<UInt16>(host_port_string.substr(pos + 1))};
}
String Cluster::Address::toFullString(bool use_compact_format) const
{
    if (use_compact_format)
    {
        if (shard_index == 0 || replica_index == 0)
            
            throw Exception("shard_num/replica_num cannot be zero", ErrorCodes::LOGICAL_ERROR);
        return "shard" + std::to_string(shard_index) + "_replica" + std::to_string(replica_index);
    }
    else
    {
        return
            escapeForFileName(user)
            + (password.empty() ? "" : (':' + escapeForFileName(password))) + '@'
            + escapeForFileName(host_name) + ':' + std::to_string(port)
            + (default_database.empty() ? "" : ('#' + escapeForFileName(default_database)))
            + ((secure == Protocol::Secure::Enable) ? "+secure" : "");
    }
}
Cluster::Address Cluster::Address::fromFullString(const String & full_string)