Issue65 add create functionality

- Adds "C"reate of the CRUD set of functionality for production type entries into the `message_broker_producer` database table.

**To test**:
- Enable module and/or `drush updb` 
- Goto `/admin/config/services/message-broker-producer/production-options`
- Add "production" entry
- Confirm entry is in production type listing at "List Productions" : /admin/config/services/message-broker-producer/list-productions