Refactor EXI_DeviceSlippi #5
Description
This is a pretty massive undertaking, so if someone wants to tackle this please make other tickets and link back to this.
The entire file is kind of a mess. It's impossible to read and logic about playing back replays, playing online and talking to the matchmaking server, rollback logic, and writing to replays are all combined together into a giant colossal stream.
Break out and architect this into a system that has clearer functionality and is easier to debug.