Fix EZP-22051: As a editor, I want content preview to work with new stack

https://jira.ez.no/browse/EZP-22051

This PR introduces new `PreviewController`, accessible by a declared route. This route overrides legacy `content/versionview` module (the iframe in admin interface).

## Custom controllers
**This patch supports custom controllers**. 

However, controllers that directly return a response (i.e. without going through the original `ViewController`) must accept the [`$params` array argument](https://github.com/ezsystems/ezpublish-kernel/blob/master/eZ/Publish/Core/MVC/Symfony/Controller/Content/ViewController.php#L92). This hash *may* contain `content` and `location` entries. `content` will then be the **previewed content**

## Tasks
* [x] Adapt various view providers and configResolver
* [x] Implement controller
* [x] Tests
* [x] Correctly manage legacy fallback
* [x] Reset legacy kernel service just before forwarding the preview request
* [x] Ensure preview siteaccess is correctly injected in container and re-inject the previous one after