Implemented: Do not expose services as REST endpoints when setting export=true in service definitions

[Criux]

Implemented: Services whose definitions set export="true" no longer automatically also create a REST endpoint that exposes the service. The goal of this change is to:

• Reduce the risk that services are implicitly exposed as REST services, when this was not the original intent of the developer
• Unify the way REST endpoints are declared by creating a *rest.xml in an OFBiz component
• Make the implementation of the rest-api component simpler

Thanks to everyone that participated in the discussion about this change here: https://lists.apache.org/thread/jhqs0b3s3bkdd7rhgzpr131c3sfxsfxj