Added real decode speed report to set it apart from the current output speed report in sample apps (#409)

* * rocDecode: Added real decode speed report.
 - The current decode speed report is actually output/display speed report.
 - Due to AV1's extensive use of alternate reference frames that are not display, AV1 decoded frame count and output/displayed frame count can be quite different, making the current speed report not an accurate decode speed measurement.
 - We now added the actual decode speed report, besides the existing speed report, now called output/display FPS.

* * rocDecode: Added real decode speed report.
 - The current decode speed report is actually output/display speed report.
 - Due to AV1's extensive use of alternate reference frames that are not display, AV1 decoded frame count and output/displayed frame count can be quite different, making the current speed report not an accurate decode speed measurement.
 - We now added the actual decode speed report, besides the existing speed report, now called output/display FPS.

* * rocDecode/Sample script: Added missing changes for sample_mode 0 case.

src/parser/av1_parser.cpp

@@ -180,6 +180,7 @@ ParserResult Av1VideoParser::ParsePictureData(const uint8_t *p_stream, uint32_t
                 ERR(STR("Failed to decode!"));
                 return ret;
             }
+            pic_count_++;
             dpb_buffer_.dec_ref_count[curr_pic_.pic_idx]--;
             memset(&tile_group_data_, 0, sizeof(Av1TileGroupDataInfo));
             if ((ret = DecodeFrameWrapup()) != PARSER_OK) {
@@ -576,7 +577,6 @@ ParserResult Av1VideoParser::DecodeFrameWrapup() {
             return ret;
         }
     }
-    pic_count_++;
     memset(&frame_header_, 0, sizeof(Av1FrameHeader));
     return ret;
 }