add create_calibrator function

[Data-Iab]

New feature : create_calibrator function that allows to create calibrator from name and kwargs is added to alonet.torch2trt to optimize imports in Tensorrt scripts.

from alonet.torch2trt import create_calibrator, DataBatchStreamer

cache_file = "calib.bin"
data_streamer = DataBatchStreamer(...)

calibrator = create_calibrator("minmax", data_streamer, cache_file)

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This pull request includes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

[thibo73800]

You can follow this format for your pull request. (should be automatic next time)
https://github.com/Visual-Behavior/aloception/blob/master/.github/pull_request_template.md