Fix panning artefacts + Cuboid custom transform control + API documentation

Source

• Graphics 2d: fix panning artefacts
• Graphics 2d: rename 'update' mode to 'edit'
• Graphics 2d/3d: handle "none" mode which allows no user interaction
• Graphics 3d: add ability to resize cuboid with opposite cuboid side as origin
• Graphics 3d: simplify transform handlers colors/opacity

Documentation

• Clean up
• Add API in graphics-2d and graphics-3d: properties / methods / events