Create a Group which is a collection of pipelines intended to run concurrently as opposed to sequentially.

Max key-value pairs a Pipiline Item can have.

Reuseable Pipeline Item pool size.

Max number of Outputs that will be allowed to processed concurrently in the pipeline.

Output queue buffer size.

We have added it here as PipelineManager is the one that passes IPipelineItems to pipelines and so must be aware of IPipelineItem.