[Feature] Own VoidGen Generator for the wolds

[Zoriot]

To remove the VoidGen Plugin Dependency Would not be needed if https://github.com/Multiverse/Multiverse-Core/pull/3110 gets merged

We actually already have the Void Gen - we just need to register PS as a Gen.

@Override
    public ChunkGenerator getDefaultWorldGenerator(String worldName, String id) { 

and return that: https://github.com/AlpsBTE/Plot-System/blob/main/src/main/java/com/alpsbte/plotsystem/core/system/plot/generator/PlotWorldGenerator.java needs to be tested though