GEOMESA-134 DTG field treatment in package object 'index' not safe

Wrap dtg variables in core.index in Options, since the temporal field in optional.
Also modify FilterToAccumulo to handle these changes.
GEOMESA-88 - Set visibilities on written data, apply authorizations to queries, allow for 3rd party service providers for authorizations
GEOMESA-136 Adding WPS processes for Geomesa Query and Geomesa Proximity Search
GEOMESA-67 Checking for visibilities before allowing write, enforcing existing schema if present