[data ops] data simulator

[TianhaoFu]

support tiny3d.lidar_simulator(data_path, expanding_method_name)

• [x] Rainy Day
• [ ] Snow Day
• [ ] Foggy Day

[TianhaoFu]

• [x] rainy: https://arxiv.org/abs/2107.07004
• [ ] fog: https://openaccess.thecvf.com/content/ICCV2021/html/Hahner_Fog_Simulation_on_Real_LiDAR_Point_Clouds_for_3D_Object_ICCV_2021_paper.html
• [ ] snow: https://arxiv.org/abs/2203.15118