Add stable diffusion fine-tuning

[itrushkin]

Summary

This PR introduces a new "Diffusion" task for image generation using LDMs.

Checklist

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

License

• [x] 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.
• [x] I have updated the license header for each file (see an example below).

# Copyright (C) 2024 Intel Corporation
# SPDX-License-Identifier: Apache-2.0

[yunchu]

@itrushkin please update base branch to apply #3882 it will resolve storage related issue on the unittest.

[kprokofi]

Hi @itrushkin , if this PR intends to be included in OTX2.3 release, it should be merged today. Otherwise, we need to postpone it for 2.4