squash #6156 (#6161)

* move common server files

* update includes with move

* create participant, move code

* fix linker errors

* fix regressions

* mark function as override to make clang happy

* split out spectator to new file

* forgot to add to cmakelists

* autocompleter picking wrong casing for var name

* clean up forwards declarations in player

* fix includes in game

common/server/server_player_reference.h

@@ -0,0 +1,33 @@
+#ifndef SERVER_PLAYER_REFERENCE_H
+#define SERVER_PLAYER_REFERENCE_H
+
+class PlayerReference
+{
+private:
+    int roomId;
+    int gameId;
+    int playerId;
+
+public:
+    PlayerReference(int _roomId, int _gameId, int _playerId) : roomId(_roomId), gameId(_gameId), playerId(_playerId)
+    {
+    }
+    int getRoomId() const
+    {
+        return roomId;
+    }
+    int getGameId() const
+    {
+        return gameId;
+    }
+    int getPlayerId() const
+    {
+        return playerId;
+    }
+    bool operator==(const PlayerReference &other)
+    {
+        return ((roomId == other.roomId) && (gameId == other.gameId) && (playerId == other.playerId));
+    }
+};
+
+#endif