Ghost roles create new minds, better tracking of roles at round end screen (#5175)

* 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

Resources/Locale/en-US/ghost/observer-role.ftl

@@ -0,0 +1,2 @@
+observer-role-name = Observer
+