Publication plugin only works with entity with 'status' property

Problem/Motivation

Status is hardcoded.
In case entities has a "published" property which is not 'status' but 'enabled' for example, plugin will not work.

Steps to reproduce

Try on entity which use a publish key other than status.

Proposed resolution

Get the entity key for "published" instead of hardcoded 'status'.
Use the EntityPublishedTrait to now if entity is published and to set publish state.