Add AsyncInsertBytes Profile Event Counter for Async INSERTs

Why it matters

This feature provides users and administrators with visibility into the volume of data being processed by asynchronous INSERTs, helping to monitor and optimize the performance and resource usage of these operations.

How to use it

Users can access the AsyncInsertBytes counter through ClickHouse's profiling and monitoring tools to observe the size metrics of async INSERT queries. No special configuration is required; the counter is available by default once the update is applied.