Fix dbus sessionList

Order the list by tab order.

ISSUE: #13
FIXED-IN: 20.12
(cherry picked from commit 358697be)

src/ViewManager.cpp

@@ -1044,8 +1044,11 @@ QStringList ViewManager::sessionList()
 {
     QStringList ids;
 
-    for (auto sdsp : _sessionMap) {
-        ids.append( QString::number( sdsp->session()->sessionId() ) );
+    for (int i = 0; i < _viewContainer->count(); i++) {
+        auto terminaldisplayList = _viewContainer->widget(i)->findChildren<TerminalDisplay *>();
+        for (auto *terminaldisplay : terminaldisplayList) {
+            ids.append(QString::number(terminaldisplay->sessionController()->session()->sessionId()));
+        }
     }
 
     return ids;

src/ViewManager.h

@@ -251,7 +251,7 @@ public Q_SLOTS:
 
     /**
      * DBus slot that returns the unique ids of the sessions in the
-     * current view.  The returned list is not sorted.
+     * current view.  The returned list is ordered by tab.
      * QList<int> is not printable by qdbus so we use QStringList
      */
     Q_SCRIPTABLE QStringList sessionList();