Add optional `msgspec <https://jcristharif.com/msgspec/>`_ support over TCP streams as an alernative, faster MessagePack codec. This get's us moving toward typed messaging/IPC protocols. Further, ``msgspec`` structs may be a valid tool to start for formalizing our "SC dialog un-protocol" messages as described in `#36 <https://github.com/goodboy/tractor/issues/36>`_`.