* Ghost roles now get new Minds
* Some round start/end button stuff
* Mind tracking for better round end reports
* Make traitor kill objectives use mind CharacterName rather than actual occupied entity ("kill brain" prevention)
* Transition over to EntityUid for mind stuff because that's the only way to do it
* BrainSystem fix for PR rebase
* GameTicker turned into an EntitySystem
* Turns ClientGameTicker into an EntitySystem, turn NetMessages into events
* Change event names to be more consistent with the rest.
* YAML linter uses the dummy gameticker CVar override.
* Fix game ticker initialization order
* Dummy ticker won't spawn players.
* Fix character creation test
