add config file for test case

cfg/partitioning/rpr_no_subpic_single_slice_per_subpic.cfg

+# example config file for a corner test case:
+# set single_slice_per_subpic_flag equal to 1, while subpicture_info_present_flag is equal to 0
+# requires special handling, when RPR is enabled (which is allowed because subpicture_info_present_flag is equal to 0) and tiles are present
+#
+# example command line:
+# ./EncoderApp -c ../cfg/encoder_randomaccess_vtm.cfg  -c ../cfg/per-sequence/RaceHorses.cfg  -q 42 -f 5 --SEIDecodedPictureHash=1 -c ../cfg/partitioning/rpr_no_subpic_single_slice_per_subpic.cfg
+
+
+ScalingRatioHor                     : 2.0   # enable horizontal scaling
+ScalingRatioVer                     : 2.0   # enable vertical scaling
+UpscaledOutput                      : 1     # upscale output
+
+EnablePicPartitioning               : 1     # enable signalling of picture partitioning
+SingleSlicePerSubpic                : 1     # single_slice_per_subpic_flag equal to 1
+RasterScanSlices                    : 0     # rectangular slices
+
+TileColumnWidthArray                : 2     # two tiles horizontally
+TileRowHeightArray                  : 2     # two tiles vertically
+
+Level                               : 6     # level increase required for small tiles (because of subsampling)