Post-game replay

[bglw]

• Send rules from server to client in the GameStateMessage
• Store rules in a depot or ActiveGame
• Store move_sequence in the core Game object (server-side as well)
• Send move_sequence to the client in the GameStateMessage
• Store move_sequence in ActiveGame
• Remove move_sequence from SinglePlayerState and use the one inside Game {}
• Add a button to go to the replay at the end of a game (or go automatically)
• Add pause/play/next/prev buttons to replay
• Add timeline scrubber to replay