Qt: Support ampersand in funnel menu and button

An ampersand in the menu item or a button is used as shortcut, so
use "&&" to get a real ampersand.


(cherry picked from commit c84681aca2)

ui/qt/funnel_statistics.cpp

@@ -58,13 +58,16 @@ static void progress_window_destroy(struct progdlg *progress_dialog);
 class FunnelAction : public QAction
 {
 public:
-    FunnelAction(const QString title, funnel_menu_callback callback, gpointer callback_data, gboolean retap, QObject *parent = nullptr) :
+    FunnelAction(QString title, funnel_menu_callback callback, gpointer callback_data, gboolean retap, QObject *parent = nullptr) :
         QAction(parent),
         title_(title),
         callback_(callback),
         callback_data_(callback_data),
         retap_(retap)
     {
+        // Use "&&" to get a real ampersand in the menu item.
+        title.replace('&', "&&");
+
         setText(title);
         setObjectName(FunnelStatistics::actionName());
     }

ui/qt/funnel_text_dialog.cpp

@@ -118,8 +118,11 @@ void FunnelTextDialog::setTextEditable(gboolean editable)
     ui->textEdit->setReadOnly(!editable);
 }
 
-void FunnelTextDialog::addButton(funnel_bt_t *funnel_button, const QString label)
+void FunnelTextDialog::addButton(funnel_bt_t *funnel_button, QString label)
 {
+    // Use "&&" to get a real ampersand in the button.
+    label.replace('&', "&&");
+
     QPushButton *button = new QPushButton(label);
     ui->buttonBox->addButton(button, QDialogButtonBox::ActionRole);
     text_button_to_funnel_button_[button] = funnel_button;

ui/qt/funnel_text_dialog.h

@@ -45,7 +45,7 @@ public:
     const char *getText();
     void setCloseCallback(text_win_close_cb_t close_cb, void* close_cb_data);
     void setTextEditable(gboolean editable);
-    void addButton(funnel_bt_t *button_cb, const QString label);
+    void addButton(funnel_bt_t *button_cb, QString label);
 
 private slots:
     void buttonClicked();