Remove methods which expose internal ID

Remove the following methods with expose internal IDs
from public view

- DatastoreExtended#getDocNumericId() - Removed from public interface
- BasicDocumentRevision#getInternalNumericId() - Changed visibiity to protected

Only one question, should the getDocNumericId on BasicDatastore remain public or be made protected?
This needs to be package private, otherwise we're leaking this identifier which the PR was supposed to hide from public view