GitLab

- as per the spconv documentation, the order of channels in weights is now changed
- we need to get all the affected weights, using the util function in spconv_utils
- we need to check the version with the version checker in __init__.py
- we need to transpose last two dimensions of existing weights, from older models
- to avoid duplication a single _load_state_dict method is added

* add voxel roi pooling

* add voxel r-cnn head

* add voxel query

* add voxel r-cnn

* add Voxel R-CNN

* add infos about Voxel R-CNN

* add voxel_rcnn_car.yaml

* add infos about Voxel R-CNN
Co-authored-by: Shaoshuai Shi <shaoshuaics@gmail.com>