app: serializers update now is reflected in Lua

There are some objects called serializers - msgpack, cjson, yaml,
maybe more. They are global objects affecting both Lua and C
modules.

A serializer have settings which can be updated. But before the
patch an update changed only C structure of the serializer. It
made impossible to use settings of the serializers from Lua.

Now any update of any serializer is reflected both in its C and
Lua structures.

Part of #4434

(cherry picked from commit fe4a8047)