Support cylinder-shaped nodes

[SOF3]

• Implement shape::Unit::contains
• Implement shape::Unit::between for Cylinder #151
• Implement shape::Unit::bb_under
• Adapt cylinder position/normal buffer for node rendering
• Add cylinder texture type
  • curve.svg: f(x, y) = (cos 2x pi, sin 2x pi, y)
  • top.svg and bottom.svg: f(x, y) = (x, y, 0 or 1), area beyond unit circle unused
• Check other places hardcoded with shape::Cube

[SOF3]

Currently all shapes use DUMMY_CUBE_SPRITES as the dummy sprite set when the texture is loading. Although inconsistent, this does not appear to be problematic since cube is the shape with the most sprites (6) compared to cylinder (3) and sphere (1).