[essentials] Disable Camunda when adding projects

If a user selects the "Projects" feature then Essentials adds the bpm.war to the deployables and (probably) distribution. Because Camunda is removed in v15 this is no longer needed.
Since 14.2 Camunda is no longer needed and can be disabled with a system property. To make sure that new projects start without Camunda we should modify Essentials:

• update script so that is no longer adds bpm.war to deployables.
• Also check that bpm.war does no longer end up in distribution.

The distribution produced with mvn -P dist will no longer contain the bpm.war and wpmDS resource. So when this distribution is deployed without the system property customers will notice that projects does not work. Then they will have to lookup the documentation and realize that they have to add this property. So as long as we document this properly it is fine that customers will have to do some post-configuration. Most likely we should document this on a troubleshooting page.