Resolve "Rework communicator stats"
Closes #205 (closed)
follow-up on Rework "Rate Stats" (#203 - closed)
Encapsulated CommunicatorMetrics in class and refactored processing Code to avoid code duplication (Manager/IceStorm-Admin). Finalized Migration to CounterAttr.
Additional Review: @usnlf_albrecht (gui)
Edited by Christian Dreher