GEOMESA-446 Wire up TDI via WPS

The only issue I know of is that the TDI process must be ran with xml as the output type currently. json does not work. Currently, we embed the json timeseries inside of the xml output (unless there is a query hint specifying to return an encoded time series object rather than the timeseries in json form).
quesiton: if a user supplies srid=xyz in their spec string will they get back 4326 without a warning? It probably would be good to have some log warning or IllegalArgException or something instead of throwing it out if that's the case.