Refactor Versioned to use more composition #421
Description
Story
As a development team, we want Versioned's logic to be composable and well structured to minimise our long term maintenance.
Context
Versioned has a lot of code that got tacked on over the years without an overarching view, e.g. RecursivePublishable was added on top of it because it didn't make the CMS 4 cut off.
The primary Versioned class is ridiculously big which makes it difficult to understand what it's trying to do.
Acceptance criteria
- Versioned is refactored with an eye to making it composable with Services.
- Common use case still work out of the box.
- Potential pitfalls with more advanced use case are called out in the changelog.
- Concerns related to GridField and UI management are moved to other module.