Add separate config directive for Buffer profile

Why it matters

This feature allows users to configure buffer profile settings independently, improving flexibility and control over buffering behavior. It solves the problem of having combined or unclear settings by providing a dedicated configuration profile for buffer parameters, thereby enhancing performance tuning and resource management.

How to use it

Users can enable and customize the Buffer profile by setting the new dedicated configuration directive in their ClickHouse configuration files, allowing fine-tuned adjustments specific to buffering needs.