[Replay] Show the history sidebar in replay tabs

Add the Game History dock to the left of replay tabs, wire it to the replay timeline, and register it with the View menu and layout reset.

cockatrice/src/interface/widgets/replay/replay_widget.h

@@ -38,6 +38,11 @@ public:
 
     [[nodiscard]] const QList<int> &getReplayTimeline() const;
 
+    /**
+     * @brief Index of the last replay event the game state has processed, or -1 before the first event.
+     */
+    [[nodiscard]] int getLastProcessedEventIndex() const;
+
 public slots:
     void seekToEvent(int eventIndex);