Add min_session_timeout_ms Setting to Clickhouse-Keeper

Why it matters

To allow clickhouse-keeper to better manage client session timeouts by considering both min_session_timeout_ms and session_timeout_ms, ensuring that session timeouts do not go below a defined minimum value. This helps improve stability and session management.

How to use it

Configure the min_session_timeout_ms setting in the clickhouse-keeper configuration file along with session_timeout_ms. Clickhouse-keeper will then determine the effective client session timeout based on these two settings.