Make Perf test available to load pervious Perf test to skip training stage

[eunwoosh]

Summary

This PR adds new features that Perf test can skip training stage by loading previous Perf test.
If previous perf test result directory is given as an argument,
Perf test can check training w/ same tags (["data_group", "data", "model", "task", "seed"]) was already done, and skip training stage if possible.
This feature can provide two use cases:

• check inference performance on various environment w/o training
• resume performance test when it's aborted after training is done

Additionally, this PR includes

• updating perf test code to measure e2e_time of test stage
• when making symbolic link for ./latest, sym link refers relative path not absolute path

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

[goodsong81]

Nice feature & refactoring!
I have a few minor comments. Feel free to accept or not (except for the typos ;p)

[goodsong81]

LGTM!