Refactor internals of Style Cartoon and Style Ribbon nodes

[BradyAJohnston]

Everything internally is now using Rotations for interpolation so it more smoothly interpolates between some of the more twisted helices and beta sheets. Sheets also use extrusion to create their arrows which fixes shading issue with the arrow heads.

• initial cleanup of cartoon nodes, use rotation internally
• more tweaking and overhaul
• mostly finished cleaning up cartoon with rotations
• cleanup
• more improvements and cleanup
• more tinkering
• more cleanup
• tweaks with ribbon creation for cylinders
• almost done!
• mostly finalised new cartoon
• cleanup ribbon
• final cleanup
• finalised
• update tests