naive: move json [en/de]code functions to common core
naive: move json [en/de]code functions to common core

ngzax/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit