Fix Dependency Injection Support for Behavior Actions

[jdrueckert]

Issue

Dependency injection via @In is a widely used mechanism throughout our code-base.
However, it doesn't seem to be supported or function properly for all kinds of classes yet.

There seems to be an implementation for Behavior Actions. Unfortunately, it doesn't seem to work as expected.
For some reason, the dependency injection sometimes (?) doesn't seem to work and the object to be injected is not initialized and stays null, resulting in an NPE when being accessed.

I don't know whether this is sufficient and if not, why. I wonder whether this might be related to the respective fields not being registered, yet, rather than the dependency injection not working as expected...?

Workaround

The current workaround for this issue is to get the dependency from CoreRegistry instead:

nightTrackerSystem = CoreRegistry.get(NightTrackerSystem.class);

This workaround gets applied to all behavior actions in Behaviors in Terasology/Behaviors#102

Additional notes

Related Issues:

• Add Dependency Injection Support for WorldGen Plugins #5003
• Roadmap for replace Pathfinding with FlexiblePathfinding #4981