GEOMESA-383 attribute index only iterator

in IteratorTrigger, the iteratorChoice.useSFFI includes 3 checks: not density, not transforms, and filter is a 'trivial pass through'. However, Filter.INCLUDE wasn't considered to be a pass through, so it would apply the SFFI. I didn't want to mess with the logic for the IndexIterator, so I added the check here. It's probably something that should go in IteratorTrigger:~99. Thoughts?