Support configurable per task waiting time

Why it matters

This feature addresses the need to manage resource allocation more granularly by allowing users to configure how long low priority queries wait per task before execution. It helps in optimizing query scheduling and improving overall system responsiveness under load.

How to use it

Users can set the waiting time for low priority queries either in the server configuration or on a per-session basis. This is done by configuring the corresponding settings that define the maximum wait time per task for low priority queries.