New cpp folder structure

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

libs/storage/country_tree_helpers.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "storage/country_tree.hpp"
+#include "storage/storage_defines.hpp"
+
+#include <optional>
+#include <string>
+
+namespace storage
+{
+// Loads CountryTree only, without affiliations/synonyms/catalogIds.
+std::optional<CountryTree> LoadCountriesFromFile(std::string const & path);
+
+// Returns topmost country id prior root id or |countryId| itself, if it's already a topmost node or
+// disputed territory id if |countryId| is a disputed territory or belongs to disputed territory.
+CountryId GetTopmostParentFor(CountryTree const & countries, CountryId const & countryId);
+}  // namespace storage