Now as the new entity field API got committed, we need to convert existing entity types to make use of it. See #1346214: [meta] Unified Entity Field API and the "Entity Field API" tag.
We decided to exploit the
EntityBCDecorator to perform a partial conversion, allowing us to convert only the key pieces of code an leave the rest to follow-ups. This in turn leads to more manageable patches and less changes in a single issue. To be able to follow this approach we need to change all type hints referring to the
Node entity to just
EntityInterface, which moreover is the recommended way according to our coding standards. This will also pave the way for #1810370: Entity Translation API improvements.