New cpp folder structure

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

libs/storage/diff_scheme/diff_scheme_loader.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "storage/diff_scheme/diff_types.hpp"
+#include "storage/storage_defines.hpp"
+
+#include <cstdint>
+#include <functional>
+#include <unordered_map>
+
+namespace storage
+{
+namespace diffs
+{
+struct LocalMapsInfo final
+{
+  using NameVersionMap = std::unordered_map<storage::CountryId, uint64_t>;
+
+  uint64_t m_currentDataVersion = 0;
+  NameVersionMap m_localMaps;
+};
+
+using DiffsReceivedCallback = std::function<void(diffs::NameDiffInfoMap && diffs)>;
+
+class Loader final
+{
+public:
+  static void Load(LocalMapsInfo && info, DiffsReceivedCallback && callback);
+};
+}  // namespace diffs
+}  // namespace storage