RimWellLogPlot_exportDataAsLas and RimWellLogPlot_exportDataAsAscii
return the exported file names. RicfExportWellLogPlotData picks the
method from the exportFormat and forwards to it. Add
RicfForwarding::findWellLogPlot().
The Python wrappers keep their signature and List[str] return value,
now calling the object methods. The misspelled export_tvdrkb argument
is kept as a deprecated alias of export_tvd_rkb.