✨ Manage TrafficSignalControllers

First implementation for managing TrafficSignalControllers directly through the engine. Declared TrafficSignalControllers are be transformed into a nodes of the behavior tree, each phase getting its own leaf.

Restrictions:

• Phases must define at least a single TrafficSignalState
• TrafficSignalGroupStates (openSCENARIO 1.2) currently not supported
• Delays and references between controllers not implemented yet