BroDynamics - Animatter Solver and Node Editor

It seems that people love nodes. So I got you some nodes.

Working on a new node UI for the upcoming BroDynamics update featuring a new custom physics solver, which I named Animatter (It's like Antimatter but Animator. See? See!?). It is a working name for now, if I find something better I'll change it. Open to ideas! Let me know in Discord if you have any ideas about what name to give this new physics engine.

Anyway, currently this new node editor supports:

• Creating, moving, deleting, connecting nodes
• Saving and Loading nodes to and from JSON (which can be used to save node editor state to file, with Maya scene or inside a Batch Simulation window of BroDynamics)
• Quality of life features like selection validation, and automatically creating sections of node networks (for example for the Chain simulation you need a Chain Node and Point Node for each object)

This is just the beginning, so still lots more work to do.