Add capacity setting for edge resp. connection

[ERnsTL]

• Some connections will pass way more IPs than other (configuration data, request data versus bulk data processing)
• Higher capacity of connections reduces number of CPU context switches, increases throughput and reduces wall clock duration for a run-through
• But increasing capacity of all connections is a waste of system memory - capacity 4 version capacity 10000.
• Solution would be an attribute on graph edges, when the runtime connections are created

Steps:

• Ability to set edge properties via noflo-ui