Add browse_dataset for visualization

[canoe-Z]

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

Fix the bug in imshow_det_rbboxes when input bboxes are without scores. Add browse_dataset for visualization.

Modification

Please briefly describe what modification is made in this PR.

BC-breaking (Optional)

Does the modification introduce changes that break the back-compatibility of the downstream repos?
If so, please describe how it breaks the compatibility and how the downstream projects should modify their code to keep compatibility with this PR.

Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases here, and update the documentation.

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. The documentation has been modified accordingly, like docstring or example tutorials.

[yangxue0827]

Thanks for your contribution. Detailed docstring should be added to all functions, you can refer to other scripts.

[canoe-Z]

Thanks for your contribution. Detailed docstring should be added to all functions, you can refer to other scripts.

Docstring has been added.

[codecov-commenter]

Codecov Report

Merging #98 (96f56a3) into dev (077ae5d) will increase coverage by 0.01%.
The diff coverage is 81.81%.

@@            Coverage Diff             @@
##              dev      #98      +/-   ##
==========================================
+ Coverage   28.96%   28.97%   +0.01%     
==========================================
  Files         104      104              
  Lines        6581     6585       +4     
  Branches      985      987       +2     
==========================================
+ Hits         1906     1908       +2     
  Misses       4609     4609              
- Partials       66       68       +2     

Flag	Coverage Δ
unittests	28.95% <81.81%> (+0.01%)	⬆️

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

Impacted Files	Coverage Δ
mmrotate/core/visualization/image.py	76.00% <81.81%> (-2.27%)	⬇️

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[zytx121]

LGTM

[jbwang1997]

LGTM