AVC: Added DPB management, decoded picture output and display callback. (#244)

* * rocDecode/AVC: Added display callback implementation.

* *rocDecode/AVC: Fixed a few issues with decoded buffer output and bumping from DPB.

* * rocDecode: Name changes based on code review.

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Co-authored-by: Kiriti Gowda <kiritigowda@gmail.com>

[ROCm/rocdecode commit: ca3333f7b9]

projects/rocdecode/src/parser/hevc_parser.h

@@ -115,7 +115,7 @@ protected:
     typedef struct
     {
         uint32_t dpb_size;  // DPB buffer size in number of frames
-        uint32_t num_needed_for_output;  // number of pictures in DPB that need to be output
+        uint32_t num_pics_needed_for_output;  // number of pictures in DPB that need to be output
         uint32_t dpb_fullness;  // number of pictures in DPB
         HevcPicInfo frame_buffer_list[HEVC_MAX_DPB_FRAMES];