add centripetal head

[tianyuandu]

No description provided.

[codecov]

Codecov Report

Merging #3390 into master will increase coverage by 0.20%.
The diff coverage is 71.10%.

@@            Coverage Diff             @@
##           master    #3390      +/-   ##
==========================================
+ Coverage   61.11%   61.31%   +0.20%     
==========================================
  Files         213      217       +4     
  Lines       15211    15608     +397     
  Branches     2587     2645      +58     
==========================================
+ Hits         9296     9570     +274     
- Misses       5446     5558     +112     
- Partials      469      480      +11     

Flag	Coverage Δ
#unittests	61.31% <71.10%> (+0.20%)	⬆️

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

Impacted Files	Coverage Δ
mmdet/models/dense_heads/corner_head.py	74.86% <ø> (+0.54%)	⬆️
mmdet/models/dense_heads/gfl_head.py	27.39% <0.00%> (-0.26%)	⬇️
mmdet/models/dense_heads/reppoints_head.py	22.34% <0.00%> (ø)
mmdet/models/detectors/reppoints_detector.py	100.00% <ø> (+75.00%)	⬆️
mmdet/models/detectors/single_stage.py	84.61% <0.00%> (-3.39%)	⬇️
mmdet/models/dense_heads/dense_test_mixins.py	15.00% <15.00%> (ø)
mmdet/core/fp16/deprecated_fp16_utils.py	46.66% <46.66%> (ø)
mmdet/models/dense_heads/anchor_head.py	85.04% <54.54%> (-1.91%)	⬇️
mmdet/models/dense_heads/centripetal_head.py	58.24% <58.24%> (ø)
mmdet/models/dense_heads/anchor_free_head.py	75.96% <75.00%> (-0.23%)	⬇️
... and 18 more

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[hellock]

Task linked: CU-4fprqd Centripetal Head

[hellock]

README and modelzoo.md should also be updated.