Optimize path assignment to handle point cloud in JSON without images

[sooahleex]

Summary

• Same as #1643
• Apply this to release/1.10.0

How to 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) 2024 Intel Corporation
#
# SPDX-License-Identifier: MIT

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Please upload report for BASE (releases/1.10.0@62bb4f4). Learn more about missing BASE report.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## releases/1.10.0 #1649 +/- ## ================================================== Coverage ? 81.11% ================================================== Files ? 283 Lines ? 32829 Branches ? 5288 ================================================== Hits ? 26628 Misses ? 4750 Partials ? 1451 ``` | [Flag](https://app.codecov.io/gh/openvinotoolkit/datumaro/pull/1649/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit) | Coverage Δ | | |---|---|---| | [ubuntu-20.04_Python-3.10](https://app.codecov.io/gh/openvinotoolkit/datumaro/pull/1649/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit) | `81.09% <100.00%> (?)` | | | [windows-2022_Python-3.10](https://app.codecov.io/gh/openvinotoolkit/datumaro/pull/1649/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit) | `81.08% <100.00%> (?)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit#carryforward-flags-in-the-pull-request-comment) to find out more.

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