Add auto-config num_classes in CLI side

[harimkang]

Summary

• Add the ability to automatically update the model.num_classes in the CLI to match the datamodule.
• Instantiate the model separately in the CLI.
• Add the --no-update-num-classes argument to disable the feature if needed.

Before: model.num_classes was a required element.

otx train --config <CONFIG> --data_root <DATASET> --model.num_classes <NUM_CLASSES>

After: don't need to update model.num_classes separately.

otx train --config <CONFIG> --data_root <DATASET>
>>> UserWarning: The `num_classes` in dataset is 2 but, the `num_classes` of model is 1000. So, Update `model.num_classes` to 2.

How to test

Checklist

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License

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  Feel free to contact the maintainers if that's a concern.
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# Copyright (C) 2023 Intel Corporation
# SPDX-License-Identifier: Apache-2.0