New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/platform/http_thread_callback.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <cstdint>
+
+namespace downloader
+{
+class IHttpThreadCallback
+{
+public:
+  virtual bool OnWrite(int64_t offset, void const * buffer, size_t size) = 0;
+  virtual void OnFinish(long httpOrErrorCode, int64_t begRange, int64_t endRange) = 0;
+
+protected:
+  virtual ~IHttpThreadCallback() = default;
+};
+} // namespace downloader