Check if item-controlling can be modeled using ECA rules

Items controlling other items means that if the controller changes its state, its controlled items also change their state and vice versa. Further, the controller is frozen to avoid circular behavior.

The change can be easily modeled using an ECA rule with the SetStateFromTriggeringItemAction.

Moreover, circular behavior needs to be avoid too when using ECA rules, so a merge would

a) Remove the unecessary concept of triggering items, and

b) Make rules more robust