Add Keypoint Detection legacy template

[kprokofi]

Summary

How to test

Checklist

• [ ] I have added unit tests to cover my changes.​
• [ ] I have added integration tests to cover my changes.​
• [ ] I have ran e2e tests and there is no issues.
• [ ] I have added the description of my changes into CHANGELOG in my target branch (e.g., CHANGELOG in develop).​
• [ ] I have updated the documentation in my target branch accordingly (e.g., documentation in develop).
• [ ] I have linked related issues.

License

• [ ] I submit my code changes under the same Apache 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: Apache-2.0

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 20.00000% with 8 lines in your changes missing coverage. Please review.

Please upload report for BASE (releases/2.2.0@dc882bf). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
src/otx/core/model/keypoint_detection.py	20.00%	8 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## releases/2.2.0 #4094 +/- ## ================================================= Coverage ? 80.60% ================================================= Files ? 276 Lines ? 27374 Branches ? 0 ================================================= Hits ? 22066 Misses ? 5308 Partials ? 0 ``` | [Flag](https://app.codecov.io/gh/openvinotoolkit/training_extensions/pull/4094/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit) | Coverage Δ | | |---|---|---| | [py310](https://app.codecov.io/gh/openvinotoolkit/training_extensions/pull/4094/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit) | `80.36% <20.00%> (?)` | | | [py311](https://app.codecov.io/gh/openvinotoolkit/training_extensions/pull/4094/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openvinotoolkit) | `80.58% <20.00%> (?)` | | 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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