Color and Molecule2

[zachcp]

• take a stab at implementing color
• realize that want fns to modify the data directly
• get a bit sidetracked by related issues: Direct Biotite to MN method BradyAJohnston/MolecularNodes#750 , A discussion on scripting with Molecular Nodes and Blender more generally BradyAJohnston/MolecularNodes#734,
• have a chat with Brady and come up with a way forwards as articulated here: Compress subclasses into simple front-facing classes BradyAJohnston/MolecularNodes#756
• Subclass Molecule so I can prototype in this repo.
• Update imports to use Molecule fns.
• Style and materials work.
• Color will get pushed off to another PR
• add .envrc for better IDE/editor experience with pixi

Note: I also copy/paste the code form this PR here.: BradyAJohnston/MolecularNodes#751