[Feature] Add Lion optimizer

[zhouzaida]

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Motivation

Add Lion optimizer from https://github.com/lucidrains/lion-pytorch

Modification

Please briefly describe what modification is made in this PR.

BC-breaking (Optional)

No

Use cases (Optional)

optim_wrapper = dict(
    type='OptimWrapper',
    optimizer=dict(type='Lion', lr=1e-4)
)

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

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@25dfe41). Click here to learn what that means.
Patch has no changes to coverable lines.

❗ Current head 636521d differs from pull request most recent head 756b524. Consider uploading reports for the commit 756b524 to get more accurate results

Additional details and impacted files

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Flag	Coverage Δ
unittests	76.66% <0.00%> (?)

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