Ability to throttle scheduler bursts on single pool

[tooptoop4]

Current issue is I have pools configured on same type of task where I can have up to max 100 pool slots of that task type running in parallel BUT I want ability to say don't START running more than 5 at a time. So ideally these tasks should be scheduled in steps.
ie
at each scheduler iteration 1 (ie 9:03:30 am) 5 tasks scheduled for the pool
at each scheduler iteration 2 (ie 9:04:00 am) 5 more tasks scheduled for the pool (so 10 currently running in the pool)
at each scheduler iteration 3 (ie 9:04:30 am) 5 more tasks scheduled for the pool (so 15 currently running in the pool)
at 9:04:42 am 3 tasks completed for the pool
at each scheduler iteration 4 (ie 9:05:00 am) 5 more tasks scheduled for the pool (so 17 currently running in the pool)
..etc

[potiuk]

repeated in #15082. Closing as duplicated.