Fixed missing __init__ files

[deleomike]

Thanks for your contribution and we appreciate it a lot. The following instructions would make your pull request more healthy and more easily get feedback. If you do not understand some items, don't worry, just make the pull request and seek help from maintainers.

Motivation

The new v1.0.rc1 update has a bug where there are no init.py files for scannet_utils or waymo_utils. This was mentioned in #1378. Despite scannet_utils or waymo_utils being in the repo, when mmdet3d is pip installed those directories are not picked up. This caused a break in a couple of places including init_model and tools/create_dataset.py

Modification

I created init.py files for scannet_utils/ and waymo_utils/ that follow the same conventions as the kitti_utils/init.py file.

BC-breaking (Optional)

This does not break back-stream compatibility.

Use cases (Optional)

No new features

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. If the modification has potential influence on downstream projects, this PR should be tested with downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
6 out of 7 committers have signed the CLA.

✅ ZCMax
✅ VVsssssk
✅ xieenze
✅ deleomike
✅ ZwwWayne
✅ Tai-Wang
❌ Subjectivist
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[codecov]

Codecov Report

Merging #1383 (f990808) into dev (a23af3c) will decrease coverage by 0.27%.
The diff coverage is 33.33%.

❗ Current head f990808 differs from pull request most recent head b22546b. Consider uploading reports for the commit b22546b to get more accurate results

@@            Coverage Diff             @@
##              dev    #1383      +/-   ##
==========================================
- Coverage   51.16%   50.88%   -0.28%     
==========================================
  Files         212      215       +3     
  Lines       18289    18400     +111     
  Branches     2980     2991      +11     
==========================================
+ Hits         9357     9363       +6     
- Misses       8375     8480     +105     
  Partials      557      557              

Flag	Coverage Δ
unittests	50.88% <33.33%> (-0.28%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
mmdet3d/core/evaluation/waymo_utils/__init__.py	0.00% <0.00%> (ø)
mmdet3d/apis/inference.py	41.34% <20.00%> (ø)
mmdet3d/core/evaluation/scannet_utils/__init__.py	100.00% <100.00%> (ø)
mmdet3d/core/post_processing/__init__.py	100.00% <0.00%> (ø)
mmdet3d/models/dense_heads/centerpoint_head.py	44.73% <0.00%> (ø)
...valuation/waymo_utils/prediction_kitti_to_waymo.py	0.00% <0.00%> (ø)
...3d/models/roi_heads/bbox_heads/parta2_bbox_head.py	68.48% <0.00%> (+0.13%)	⬆️
mmdet3d/core/bbox/structures/base_box3d.py	71.71% <0.00%> (+0.14%)	⬆️
...odels/roi_heads/bbox_heads/point_rcnn_bbox_head.py	30.66% <0.00%> (+0.17%)	⬆️
... and 4 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a23af3c...b22546b. Read the comment docs.

After changing the base to dev, need to merge dev into this branch or merge master into dev

[ZwwWayne]

Hi @deleomike ,
Thanks for your kind contribution, could you rebase this branch to dev so that we can merge this PR to dev?

[OpenMMLab-Assistant003]

Dear deleomike,
First of all, we want to express our gratitude for your significant PR in the MMDetection3D project. Your contribution is highly appreciated, and we are grateful for your efforts in helping improve this open-source project during your personal time. We believe that many developers will benefit from your PR.
If you are Chinese or have WeChat，welcome to join our community on WeChat. You can add our assistant ：openmmlabwx. Please add "mmsig + Github ID" as a remark when adding friends：）
We would also like to invite you to join our Special Interest Group (SIG) private channel on Discord, where you can share your experiences, ideas, and build connections with like-minded peers. To join the SIG channel, simply message moderator— OpenMMLab on Discord or briefly share your open-source contributions in the #introductions channel and we will assist you. We look forward to seeing you there! Join us ：https://discord.gg/raweFPmdzG
Thank you again for your contribution❤
Best regards！ @deleomike