INTERNAL: Return a new descriptor project.
Implements abstract org.eclipse.persistence.internal.sessions.factories.NamespaceResolvableProject.buildDescriptors.
INTERNAL:
Overrides org.eclipse.persistence.internal.sessions.factories.NamespaceResolvableProject.getPrimaryNamespace.
Overrides org.eclipse.persistence.internal.sessions.factories.NamespaceResolvableProject.getPrimaryNamespacePrefix.
Overrides org.eclipse.persistence.internal.sessions.factories.NamespaceResolvableProject.getSecondaryNamespace.
Overrides org.eclipse.persistence.internal.sessions.factories.NamespaceResolvableProject.getSecondaryNamespacePrefix.