Suggestion: May create less filled volume

[ZDF77]

As Roberto G. explained to me by email: "the hull of the spaceship is created as a filled volume, which is then (organically) smoothed out. Removing internal blocks (i.e.: blocks that are internal to the hull but outside of the spaceship's inner corridors) can be done, ideally it would be some method after this line of code". LINK: https://github.com/GoodAI/space-engineers-ai-spaceship-generator/blob/main/pcgsepy/hullbuilder.py#L731

I think it would be a great improvement as QOL for the user if the hull was not filled with so many blocks from the inside. For example, you could enable an option to specify how thick the outer shell should be (1,2 or 3 blocks thick as an example) or generally implement a function that enables less blocks left inside.

I am sure you will find a good solution. Thanks a lot for your work!