Handle HiveTableFunctionScan at return path

The optimizedOptiqPlan at CalcitePlanner.getOptimizedHiveOPDag is ultimately generated by CalcitePlanner.internalGenSelectLogicalPlan, which may either provide a HiveProject or a HiveTableFunctionScan. When HiveCalciteUtil.getTopLevelSelect is invoked on this it is looking for a HiveProject node in the tree, which if won't find in case of a HiveTableFunctionScan was returned. This is why TestNewGetSplitsFormat is failing with return path.