[Fix] switch mmaction2totorchserve from mmcv to mmengine

[austinmw]

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Motivation

Fix deploy script for v1.0

Modification

switch mmcv to mmengine where appropriate

Checklist

1. Pre-commit or other linting tools should be used to fix the potential lint issues.
2. The modification should be covered by complete unit tests. If not, please add more unit tests 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 should be modified accordingly, like docstring or example tutorials.

[CLAassistant]

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[ly015]

Thank you very much for contributing to mmaction2.0. We will review this PR asap. Meanwhile, could you please sign the CLA so we can merge your code into mmaction2?