Workflow configurable managed object type

Workflow is currently hard coded to use managed/user and managed/group. We should make these configurable in conf/workflow.json.

See org.forgerock.openidm.workflow.activiti.impl.engine.SharedIdentityService:

    static final String USER_PATH = "managed/user/";
    static final String GROUP_PATH = "managed/group/";

Also need to check for hard-coded managed types in endpoint*.json scripts related to Workflow.

The sample BPMN XML files do not necessarily need to be updated, because customers could change their own XML files, but they would need to be tested with alternative managed objects.

NOTE: the scripts for these BPMN XML files have access to identityServer but there are some XML properties affected that are not scripts or EL expressions