Bugfix for explore cli test to get datasetitem through path

[sooahleex]

Summary

• Due to train_path not matched with dataset._source_path, query is considered as string input, not coverted to Datasetitem or could not bring the proper Datasetitem which is matched with path through dataset.get_datasetitem_by_path(args.query).
• Match train_path of CLI path as `project/source-1/images/train/1.jpg'.

How to test

• I fixed the path in integration test.

Checklist

• I have added unit tests to cover my changes.​
• I have added integration tests to cover my changes.​
• I have added the description of my changes into CHANGELOG.​
• I have updated the documentation accordingly

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below).

# Copyright (C) 2023 Intel Corporation
#
# SPDX-License-Identifier: MIT

[vinnamkim]

I recommend you to break the query explicitly into two cases:

1. DatasetItem id (--query-item-id)
2. Arbitrary image file path (not constrained to the project or dataset) (--query-img-path)

[vinnamkim]

Please add subset = None argument to this function and CLI argument parser. Then, iterate over subsets only if subset == None. In addition, I think this code should have a problem if there is no item for the given query_id. You need to raise an appropriate error in this case.

[vinnamkim]

LGTM.