**Describe the solution you'd like**

We already can run clickhouse-server without configured ZooKeeper (the tables will start in read-only mode)
and with configured ZooKeeper, if it starts to be inaccessible at runtime (the tables will be read-only until the session is re-established).

Let's also make it possible to start up when ZooKeeper is unavailable.

**Additional context**

If that will be very hard to implement, we can consider other options:
- lazy attaching of the tables after sever start-up;
- a maintenance mode when the tables are not attached at start-up and require manual ATTACH queries.
futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/quorum", String(), zkutil::CreateMode::Persistent));
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/quorum/last_part", String(), zkutil::CreateMode::Persistent));
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/quorum/failed_parts", String(), zkutil::CreateMode::Persistent));
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/mutations", String(), zkutil::CreateMode::Persistent));
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/quorum/parallel", String(), zkutil::CreateMode::Persistent));
    
    const auto settings = getSettings();
    if (settings->allow_remote_fs_zero_copy_replication)
    {
        futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/zero_copy_s3", String(), zkutil::CreateMode::Persistent));
        futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/zero_copy_s3/shared", String(), zkutil::CreateMode::Persistent));
        futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/zero_copy_hdfs", String(), zkutil::CreateMode::Persistent));
        futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/zero_copy_hdfs/shared", String(), zkutil::CreateMode::Persistent));
    }
    
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/part_moves_shard", String(), zkutil::CreateMode::Persistent));
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/pinned_part_uuids", getPinnedPartUUIDs()->toString(), zkutil::CreateMode::Persistent));
    
    futures.push_back(zookeeper->asyncTryCreateNoThrow(zookeeper_path + "/alter_partition_version", String(), zkutil::CreateMode::Persistent));
    for (auto & future : futures)
    {
        auto res = future.get();
        if (res.error != Coordination::Error::ZOK && res.error != Coordination::Error::ZNODEEXISTS)
            throw Coordination::Exception(fmt::format("Failed to create new nodes at {}", zookeeper_path), res.error);
    }
}
bool StorageReplicatedMergeTree::createTableIfNotExists(const StorageMetadataPtr & metadata_snapshot)