Add hostname_levenshtein_distance load balancing mode

Why it matters

This feature adds a load balancing mode that distributes queries based on the Levenshtein distance between hostnames. It helps optimize query routing and resource utilization by favoring hosts with hostnames closer to the client's hostname, improving overall load distribution and potentially reducing latency.

How to use it

To enable this feature, set the load balancing mode to hostname_levenshtein_distance in your ClickHouse client or server configuration where load balancing is configured.