[Refactor] Refactor code structure and docstrings (#803)

* refactor points_in_boxes

* Merge same functions of three boxes

* More docstring fixes and unify x/y/z size

* Add "optional" and fix "Default"

* Add "optional" and fix "Default"

* Add "optional" and fix "Default"

* Add "optional" and fix "Default"

* Add "optional" and fix "Default"

* Remove None in function param type

* Fix unittest

* Add comments for NMS functions

* Merge methods of Points

* Add unittest

* Add optional and default value

* Fix box conversion and add unittest

* Fix comments

* Add unit test

* Indent

* Fix CI

* Remove useless \\

* Remove useless \\

* Remove useless \\

* Remove useless \\

* Remove useless \\

* Add unit test for box bev

* More unit tests and refine docstrings in box_np_ops

* Fix comment

* Add deprecation warning

mmdet3d/models/segmentors/base.py

@@ -78,7 +78,7 @@ class Base3DSegmentor(BaseSegmentor):
         Args:
             data (list[dict]): Input points and the information of the sample.
             result (list[dict]): Prediction results.
-            palette (list[list[int]]] | np.ndarray | None): The palette of
+            palette (list[list[int]]] | np.ndarray): The palette of
                 segmentation map. If None is given, random palette will be
                 generated. Default: None
             out_dir (str): Output directory of visualization result.

mmdet3d/models/voxel_encoders/pillar_encoder.py

@@ -33,7 +33,7 @@ class PillarFeatureNet(nn.Module):
             Defaults to dict(type='BN1d', eps=1e-3, momentum=0.01).
         mode (str, optional): The mode to gather point features. Options are
             'max' or 'avg'. Defaults to 'max'.
-        legacy (bool): Whether to use the new behavior or
+        legacy (bool, optional): Whether to use the new behavior or
             the original behavior. Defaults to True.
     """