parser high level class implementation (#10)

* rocDecode api defintions added for decoder and parser

* addressed review comments and changed struct names to CamelCase

* minot reformatting

* parser high level class implementation

[ROCm/rocdecode commit: 0a991c1776]

projects/rocdecode/api/rocdecode.h

@@ -62,7 +62,8 @@ typedef enum rocDecStatus_enum{
     ROCDEC_OUTOF_MEMORY = -4,
     ROCDEC_INVALID_PARAMETER = -5,
     ROCDEC_NOT_IMPLEMENTED = -6,
-    ROCDEC_NOT_SUPPORTED = -7,
+    ROCDEC_NOT_INITIALIZED = -7,
+    ROCDEC_NOT_SUPPORTED = -8,
     ROCDEC_SUCCESS = 0,
 }rocDecStatus;