Reduce ORANGE construction time

[sethrj]

• Use a 2D grid for deduplication. Each dimension must be set up so that any two surfaces that are "soft equivalent" must be in the same or neighboring (including diagonal) cells
• Cache and reuse the transformation+object stack in the volume builder since solids/shapes get reused sometimes (but figure out first how much duplication there is in practice: maybe number of solid "build" calls compared to number of solids for each experiment?)