GEOMESA-177 Insert waypoints in large Geoserver BBOXs

In order to support GeoServer queries and Spatial4j's IDL handling,
this pr rewrites large BBOXs to have waypoints.
GEOMESA-185 Fix TemporalIndexCheckTest

Use functions to generate the test SFTs to avoid state between test fragments.

Also modify the test codebase to remove triggers of the TemporalIndexCheckTest, and
remove a few new references to geomesa_index_* as an attribute name.
GEOMESA-169 fixing density iterator, restoring expansion of density map

* Fixes a regression in the density iterator.
* Improves the DensityIterator unit tests.