Plugins [Experimental] Soft Physics for Inner Vagina 3

A lot of various improvements with this update. In general it should behave a lot better.

• Tweaked various physics settings. Should wobble less and overall look better.
• Added sliders for configuring physics.
  • Let me know what settings work best for you!
• Fixed issue where physics behavior would be different based on the model's orientation.
  • This was actually due to me not setting the 'anchors' properly for each vertex, so the simulation didn't know which way they were pointing. I'm still probably doing it wrong, but it seems better for now.
• Enabled threading, so hopefully it should overall be more performant.
• Reduced the number of links between vertices from its 6 nearest neighbors to 4. Should help perf and doesn't seem to affect the behavior much.
• Fixed issue with reloading that previously caused multiple meshes to get created.

So after a bit more work I've figured out how to add new soft physics meshes at runtime. You can now add this to a model like a regular plugin and it'll get saved/loaded in scenes.

I've kept the option to add it as a Scene Plugin as well in case someone prefers it for some reason.