Allow getting auxiliary_zookeepers data from system

Why it matters

This feature enables users to access detailed auxiliary_zookeepers data directly via the system.zookeeper table, providing enhanced visibility into auxiliary ZooKeeper instances connected to ClickHouse. It helps in better monitoring and managing distributed coordination components.

How to use it

Query the system.zookeeper table to obtain auxiliary_zookeepers information as part of the table's available data. For example:

SELECT auxiliary_zookeepers FROM system.zookeeper;