Function planetkit::movement::step_backward_and_face_neighbor

pub fn step_backward_and_face_neighbor(
    pos: &mut GridPoint3, 
    dir: &mut Dir, 
    resolution: [GridCoord; 2], 
    last_turn_bias: &mut TurnDir
) -> Result<(), ()>

Move backward by one cell and ensure dir now points to a legal direction for continued movement.

This by design un-does any movement and rotation performed by stepping forwards.

See step_forward_and_face_neighbor for more details`.