make it visible if entity is created via content pack

It should be visible if a processing rule or other entity is created via content pack.

## Context
Currently it is not possible to know if a rule, pipeline or similar is create via contentpack.

That creates shakiness about the content in Graylog. When multiple Persons work in Graylog you can't be sure of something is created locally or imported.

The indicator that was given in the previous version of the content packs was nice for that.

## Your Environment
* Graylog Version: 3.x