fix(chatform): name in window title and close detached chats

This displays the name of the currently used account in the window title
of detached chats. Also closes all open chats when switching back to one
window.

src/widget/contentdialog.cpp

@@ -109,6 +109,7 @@ ContentDialog::ContentDialog(QWidget* parent)
 
     setMinimumSize(minSize);
     setAttribute(Qt::WA_DeleteOnClose);
+    setObjectName("detached");
 
     QByteArray geometry = s.getDialogGeometry();
 
@@ -121,6 +122,8 @@ ContentDialog::ContentDialog(QWidget* parent)
     SplitterRestorer restorer(splitter);
     restorer.restore(s.getDialogSplitterState(), size());
 
+    username = Core::getInstance()->getUsername();
+
     currentDialog = this;
     setAcceptDrops(true);