Smart engine - Ability to start/stop triggers based on engine load

[vijaynalawade]

Current behavior:
When runner type is set to POOLED, trigger goroutines are blocked when runner queue is full.
Expected behavior:
Some mechanism where app triggers can be temporarily stopped when queue is full and started back when queue is relatively empty.
What is the motivation / use case for changing the behavior?
This feature will help control event flow when actions are slow in execution.
Additional information you deem important (e.g. I need this tomorrow):