GEOMESA-101 Optimize geometry only queries in iterator

GEOMESA-101 Optimize geometry only queries in iterator
    
    Add an IndexIterator to the iterator stack which is run in place of the SpatioTemporalIntersectingIterator AND the SimpleFeatureFilteringIterator.
    
    The trigger for this action is a query which satisfies the following:
    1) Defines a transform which projects ONLY the geometry and temporal attributes used in the GeoMesa index
    2) Filters on only the geometry and temporal attributes, and can be distilled into the selection of a polygon and interval.
    
    If the above requirements are met, the IndexIterator is run and a message indicating such is logged.

Nitpick: put a space between map and {

```scala
transformSchema.map { schema => ... }
```