Add extrude

[lcw]

• Add number of dimension to BrickGrid
• Add similar function for cells
• Don't use a startup image for formatter git hook
• Add an extruded brick coarse grid type
• Add extruded helper functions to coarse grid
• Protect ghosts from GC for unsafe use
• Pass # of local elements when materializing points
• Generate extruded brick grids
• Update CUDA.jl to support SA bounds checking
• Add extrude tests