This is to make it easier to interpolate with other tools and projects,
and to reduce the mental barrier (of me and other contributors) of
changing these. This only ports the Lobby connection to use JSON so far,
the World connection is next.
This is unfortunately lumped into one big commit, and is very hacky and WIP but
does indeed work! Since the Lobby and World server are two separate servers, it
uses it's own custom IPC packets (reusing the same packet structures as regular
game ones.)
The characters you create in the Lobby server are now saved in the World server,
but this is not yet reflected in the Lobby screen.
My old setup of throwing *all* of the IPC types and opcodes into *one* enum was
becoming unbearable. Now that we have multiple things using the same opcodes
(because they can overlap) I think it's time to repay this technical debt.
This overhauls the structure of the project to move IPC structs into their own
modules, and separate the opcode data/lists into separate ones depending on if
it's clientbound and serverbound.
Nothing has changed functionall, but this is going to make it way easier to add
more IPC in the future.
