Renamed cellindex to gridLocalCellIndex
riTRANSXYZ: Moving the calculation  to ReservoirCellResultsStorage

Create stored native riTRANX,Y,Z results instead of doing everyting in
one go.
This makes the statistics calculation work automatically instead of
beeing custoized and require a compplete calculation of its own.
riTRANSXYZ: First version working

Not yet extensively tested, but seems ok for complete match faces