New cpp folder structure

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

libs/base/internal/message.cpp

@@ -0,0 +1,20 @@
+#include "message.hpp"
+
+#include <utf8/unchecked.h>
+
+namespace internal
+{
+std::string ToUtf8(std::u16string_view utf16)
+{
+  std::string utf8;
+  utf8::unchecked::utf16to8(utf16.begin(), utf16.end(), std::back_inserter(utf8));
+  return utf8;
+}
+
+std::string ToUtf8(std::u32string_view utf32)
+{
+  std::string utf8;
+  utf8::unchecked::utf32to8(utf32.begin(), utf32.end(), std::back_inserter(utf8));
+  return utf8;
+}
+}  // namespace internal