Deprecate advanced streaming functions (#3408)

* deprecate advanced streaming functions

* remove internal usage of the deprecated functions

* nit

* suppress warnings in tests/zstreamtest.c

* purge ZSTD_initDStream_usingDict

* nits

* c90 compat

* zstreamtest.c already disables deprecation warnings!

* fix initDStream() return value

* fix typo

* wasn't able to import private symbol properly, this commit works around that

* new strategy for zbuff

* undo zbuff deprecation warning changes

* move ZSTD_DISABLE_DEPRECATE_WARNINGS from .h to .c

programs/fileio.c

@@ -1995,7 +1995,8 @@ static dRess_t FIO_createDResources(FIO_prefs_t* const prefs, const char* dictFi
     /* dictionary */
     {   void* dictBuffer;
         size_t const dictBufferSize = FIO_createDictBuffer(&dictBuffer, dictFileName, prefs);
-        CHECK( ZSTD_initDStream_usingDict(ress.dctx, dictBuffer, dictBufferSize) );
+        CHECK( ZSTD_DCtx_reset(ress.dctx, ZSTD_reset_session_only) );
+        CHECK( ZSTD_DCtx_loadDictionary(ress.dctx, dictBuffer, dictBufferSize) );
         free(dictBuffer);
     }