**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.
{
                std::lock_guard lock(last_broken_disks_mutex);
                if (!last_broken_disks.insert(disk_ptr->getName()).second)
                    continue;
            }
            LOG_INFO(log, "Scanning parts to recover on broken disk {} with path {}", disk_ptr->getName(), disk_ptr->getPath());
            if (!parts)
                parts = std::make_unique<DataPartsVector>(getDataPartsVectorForInternalUsage());
            for (auto & part : *parts)
            {
                if (part->data_part_storage && part->data_part_storage->getDiskName() == disk_ptr->getName())
                    broken_part_callback(part->name);
            }
            continue;
        }
        else
        {
            {
                std::lock_guard lock(last_broken_disks_mutex);
                if (last_broken_disks.erase(disk_ptr->getName()) > 0)
                    LOG_INFO(
                        log,
                        "Disk {} with path {} is recovered. Exclude it from last_broken_disks",
                        disk_ptr->getName(),
                        disk_ptr->getPath());
            }
        }
    }
}
bool StorageReplicatedMergeTree::canUseAdaptiveGranularity() const