Implement `namespace Serialization` approach for `Read`/`WriteStream`'s

**Issue description:**
Currently, you can implement custom JSON serialization through a clever usage of a shared namespace with the engine like this -> https://docs.flaxengine.com/manual/scripting/cpp/serialization.html#custom-types
The problem is, this only applies for the JSON and only for JSON, while there are classes like `Read` and `WriteStream`, which since introduction of networking in the engine also require some overrides in order to support small types with `NetworkReplicated` attribute.