OpenFileGDB: fix ResetReading() on SQL layer with ORDER BY on indexed column (#5669)

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@27750 f0d54148-0727-0410-94bb-9a71ac55c965
test_ogrsf: run TestOGRLayerRandomRead() and TestOGRLayerSetNextByIndex() even if OLCRandomRead or OLCFastSetNextByIndex are not declared; make TestOGRLayerRandomRead() test backward FID seeking

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@27752 f0d54148-0727-0410-94bb-9a71ac55c965