Update `ApiContentControllers::list()` to expose available content entity operations in `meta`

> Update all of our API responses (both GET individual and GET list) to provide the entity operations' link relationship for those operations that are permitted

There's no individual GET for ApiContentControllers. I don't think this should be also on auto-saved data, so this should be good now?

What a fantastic start! 🤩👏

The only failing test is because of 📌 Cypress test publish-validation is flaky Active

Very close!