Design metadata versioning system

[Code-Eat-Rabbit]

### Describe your changes:

This PR introduces a new comprehensive technical whitepaper titled `SCHEMA_EVOLUTION_WHITEPAPER.md` to the project's root directory.

I worked on generating this in-depth document to detail OpenMetadata's Schema Evolution architecture, including its database design, change detection (diff) logic, and event/notification system. The purpose is to provide a foundational understanding and practical guidance for developers and architects looking to build similar metadata versioning systems using Java/Spring Boot and MySQL, drawing heavily from OpenMetadata's proven design philosophies and implementations.

As this is a new documentation file, no code changes were made, and thus no specific code testing was performed. The content itself was generated and reviewed for accuracy and completeness.

#
### Type of change:
- [ ] Bug fix
- [ ] Improvement
- [ ] New feature
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [x] Documentation

#
### Checklist:
- [x] I have read the [**CONTRIBUTING**](https://docs.open-metadata.org/developers/contribute) document.
- [ ] My PR title is `Fixes <issue-number>: <short explanation>` (No issue number for this documentation addition)
- [ ] I have commented on my code, particularly in hard-to-understand areas. 
- [ ] For JSON Schema changes: I updated the migration scripts or explained why it is not needed.

<!-- Based on the type(s) of your change, uncomment the required checklist 👇 -->

<!-- Documentation -->
- [x] I have updated the documentation.

---

 

[cursor]

Cursor Agent can help with this pull request. Just @cursor in comments and I'll start working on changes in this branch.
_{Learn more about Cursor Agents}

[github-actions]

Hi there 👋 Thanks for your contribution!

The OpenMetadata team will review the PR shortly! Once it has been labeled as safe to test, the CI workflows
will start executing and we'll be able to make sure everything is working as expected.

Let us know if you need any help!