[Improvement] Add allocator for trt and fix DCNv2 trt implementation on dev-1.x

[hanrui1sensetime]

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Motivation

Sync #1493 feature on dev-1.x branch

Modification

-[x] Add allocator for trt
-[x] Fix DCNv2 trt implementation, which solved #972 in dev-1.x.

BC-breaking (Optional)

None.

Use cases (Optional)

Same to #1493

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 tests to ensure the correctness.
3. If the modification has a dependency on downstream projects of a newer version, this PR should be tested with all supported versions of downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[AllentDan]

LGTM