<!-- Contributing guide: https://github.com/openvinotoolkit/datumaro/blob/develop/CONTRIBUTING.md -->

### Summary
<!--
Resolves #111 and #222.
Depends on #1000 (for series of dependent commits).

This PR introduces this capability to make the project better in this and that.

- Added this feature
- Removed that feature
- Fixed the problem #1234
-->

### How to test
<!-- Describe the testing procedure for reviewers, if changes are
not fully covered by unit tests or manual testing can be complicated. -->

### Checklist
<!-- Put an 'x' in all the boxes that apply -->
- [ ] I submit my changes into the `develop` branch
- [ ] I have added description of my changes into [CHANGELOG](https://github.com/openvinotoolkit/datumaro/blob/develop/CHANGELOG.md)
- [ ] I have updated the [documentation](
  https://github.com/openvinotoolkit/datumaro/tree/develop/docs) accordingly
- [ ] I have added tests to cover my changes
- [ ] I have [linked related issues](
  https://help.github.com/en/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword))

### License

- [ ] I submit _my code changes_ under the same [MIT License](
  https://github.com/opencv/cvat/blob/develop/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)

```python
# Copyright (C) 2020 Intel Corporation
#
# SPDX-License-Identifier: MIT
```