Make scheduler job delay configurable

Description

Fixed an issue that caused a "drift" in scheduled job times due to delays employed to reduce risk of resource starvation.

When several jobs have approximately the same scheduled execution time, the scheduler service adds a delay of 10 seconds between each job execution to reduce the risk of resource starvation (for example thread).

However if there are many short-lived jobs that are scheduled with a short time interval then they might "drift" in start time due to this delay; for example, runs every third minute instead of every minute as it was scheduled.

You can configure the delay configurable to define a shorter interval if it suits your jobs better.