ClickHouse-server Removes delete_tmp Directories on Startup

Why it matters

This feature addresses the issue where residual delete_tmp directories from previous operations accumulate and require manual cleanup. By removing these directories on server start, it ensures a cleaner environment, prevents potential disk space issues, and improves server stability.

How to use it

No explicit user action is required. The cleanup of delete_tmp directories happens automatically every time the clickhouse-server starts.