Connect multiple ports more easily

Currently, one will have to select ports in order if more than two ports should be connected in one step. It may make sense to relax this to only having one output in the selection.

added Scheduling GUI label

added SFG GUI label and removed Scheduling GUI label

added Enhancement label

changed milestone to %Lab trial

There also seems to be a bug here as one can connect multiple input ports in certain situations.

assigned to @ollha42

mentioned in commit 7d3b5201

mentioned in commit bc82b9f6

mentioned in merge request !186 (merged)

mentioned in commit 7c94e73b

mentioned in commit 2c0582c4

mentioned in commit 6bc7cbcd

mentioned in commit 217cadbf

closed with merge request !193 (merged)