refs 5fd2b7fed1
- sends `?send_email_when_published=true` query param when scheduling/publishing a post with the toggle turned on
- adds support to the posts adapter for handling the `adapterOptions` option
- updates the editor `save` task to pass through the required adapter option when a post is being published or scheduled with the toggle checked
- moves state for the email toggle into the publish menu so that we don't try to toggle the model attribute which should only be fetched from the API
- prevent `post.send_email_when_published` being sent to the API via the serializer as it's now a read-only attribute
