Initial implementation of Sandworms (WIP; Need help with audio and animations)

Using Mailaender's code as basis, this is my implementation of the sandworm behavior. It is still WIP, but you can get an idea of how it looks from the shellmap.
I'm talking about partially working audio/video stuff. I will get the logic done before merging.
Otherwise anyone can help fix them in this PR. I'm personally just too far away from the visual stuff and I currently don't know what to do with the audio notifications. I'd rather let someone else fix them in 10 minutes while I work on spice blooms (my next goal) than spend a few days trying to do them myself.