Add support for passive claims in LSAT

In some situations, an activity can only execute if some resources are guaranteed to be idle. For example, in a system with a belt and two pick-and-place robots, we want to ensure that either the belt is moving or the robots are performing an operation. If the robots are operating, then the belt must be standing still. If the belt is moving, then the robots are not allowed to perform an operation.

Currently in LSAT, a resource can only be claimed by one activity at a time. LSAT could be extended with a notion of passive claims. Multiple activities can passively claim the same resource at the same time. The resource can only perform an action once all passive claims are released, and it is claimed by an activity.