Implement Apache Flink - FLIP-400: AsyncScalarFunction for asynchronous scalar function support.

Implement Apache Flink - FLIP-400: AsyncScalarFunction for asynchronous scalar function support.: a task in LoLBench (Harbor dataset). You are working in /workspace/flink , a source tree checked out at the base commit for this task. Implement the requested behavior in the source tree, then run:

The task

You are working in `/workspace/flink`, a source tree checked out at the base commit for this task. Implement the requested behavior in the source tree, then run:

Part of lolbench26/LoLBench.