[Server/Client/Protocol] Shuffle or reorder player seats before a game starts (#7398)

* [Protocol] Add shuffle players option and player order command/event

Adds a 'Shuffle players at start' option to game creation plus a local
player id on the game state so clients can reconcile seat changes, and a
SET_PLAYER_ORDER command (1206) with a PLAYER_ORDER_CHANGED event (2023)
so the game host can set or randomize the seating order.

Took 6 minutes

* [Server] Shuffle and reorder player seats before a game starts

Auto-shuffles the seats at game start when enabled (now for games with
two or more players instead of three or more) and handles the new
SET_PLAYER_ORDER command so the game host or a moderator can reorder or
randomize the seats before the game starts. Re-seating re-keys the
player ids while keeping the per-user game/seat routing and persistent
player records in sync, then broadcasts the new order to everyone.

* [Client] Add shuffle players option and turn order dialog

Adds the 'Shuffle players at start' checkbox to game creation and a
host-only 'Set turn order...' action that opens a dialog to reorder or
randomize the seats before the game starts. Seating changes are shown in
the game's message log.

* [Client] Move the turn order dialog strings into retranslateUi

Follows the DlgInviteToGame convention so the dialog can be retranslated
instead of freezing its strings at construction time.

* [Server] Keep player ids stable across seat shuffles

* [Client] Lay out table and turn order dialog in seat order

* [Server] Send game-joined player list in seat order

* [Client] Reword the shuffle option to match its behaviour

* [Client] Address the seat-order review comments

- Give the game setup checkboxes a row of their own so they no longer
  collide in the create-game dialog
- Rename DlgTurnOrder::randomize() to isRandomizeRequested()
- Document what the ids in GameState::seatOrder mean
- Keep "Set turn order..." in sync with the game: hidden for non-hosts
  and once the game has started, re-shown when the game ends or hosting
  moves to the local player (new GameState::hostChanged signal)

* [Client] Do not preview a randomized turn order

Randomizing is a request to the server, not a local shuffle. Shuffling the
list locally meant the dialog showed an order the server then discarded, and
let the host re-open it until a favourable order appeared. The dialog now
switches to a mode that says the server will randomize and toggles back to the
manual list on request.

* [Client] Let moderators set the turn order

The server accepts SET_PLAYER_ORDER from the host or a moderator, but the
client hid the action from everyone except the host, making the moderator
branch unreachable. Visibility and the handler now share canSetTurnOrder().

* [Server] Rely on the player order event instead of a full state resend

cmdSetPlayerOrder re-sent the whole game state after reseating, so every
client reloaded its deck view mid-lobby for no reason. The new seating reaches
clients through the Event_PlayerOrderChanged that reseatPlayers broadcasts.

* [Client] Show random turn order in the game selector

The restrictions column listed "open decklists" but not the new seating
option, so a joining player had no way to see that seats will be randomized
each game. Game info already shows the disabled checkbox.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/interface/widgets/dialogs/dlg_turn_order.h

@@ -0,0 +1,51 @@
+/**
+ * @file dlg_turn_order.h
+ * @ingroup GameDialogs
+ */
+//! \todo Document this file.
+
+#ifndef DLG_TURN_ORDER_H
+#define DLG_TURN_ORDER_H
+
+#include <QDialog>
+#include <QStringList>
+
+class QLabel;
+class QListWidget;
+class QPushButton;
+
+class DlgTurnOrder : public QDialog
+{
+    Q_OBJECT
+private:
+    QListWidget *listWidget;
+    QLabel *hintLabel;
+    QPushButton *moveUpButton;
+    QPushButton *moveDownButton;
+    QPushButton *randomizeButton;
+    bool randomizeRequested;
+
+    void moveSelected(int delta);
+    void updateMode();
+    void updateButtons();
+
+private slots:
+    void actMoveUp();
+    void actMoveDown();
+    void actRandomize();
+    void actOk();
+    void selectionChanged();
+
+public:
+    explicit DlgTurnOrder(const QStringList &_playerNames, QWidget *parent = nullptr);
+
+    void retranslateUi();
+
+    [[nodiscard]] bool isRandomizeRequested() const
+    {
+        return randomizeRequested;
+    }
+    [[nodiscard]] QStringList order() const;
+};
+
+#endif