Work out custom serialization

[Reousa]

Do further research & assess whether just rset and rpc will work for the entirety of the game.

• Apparently godot's current serialization methods can include script code, which opens the recepient up to remote code execution at worst.

• Godot serializes data types including Dictionaries and Arrays. Worthwhile to take a look at the source code.

Related to: #276