Cleaning and bug fixes

Description of refactor

Huge dead code cleaning, little refactor based on 2.93 and some features bug fixing.

• Removed clean_outdated_cache.
• get_parent_metas renamed as get_metas_hierarchy.
• Removed utils_openreviewio.py
• autosave moved to load_handler.

How to test it

Checklist

Please check if your MR fulfills the following requirements:

• Unit tests have been adapted
• Build was run locally and any changes were pushed
• Lint has passed locally without error
• CHANGELOG.md has been updated

FYI: @awesome_dev_too