Support 3D data

[zhiltsov-max]

Vision datasets often include 3d data - it can be lidar, MRI, landscape, buildings and models. It would be nice is Datumaro could handle such datasets. Examples: BRATS, KITTI, ObjectNet3D, MVTec ITODD, T-LESS, Falling Things

[zhiltsov-max]

Added point clouds in #245