When dragging and dropping tabs, move new window to cursor positon

This fixes multiple monitor issues - dnd window will be moved to where
user dropped the window.

BUG: 324760
FIXED-IN: 2.13
(cherry picked from commit e6dcc8d6b8)

src/Application.cpp

@@ -89,6 +89,9 @@ void Application::detachView(Session* session)
 {
     MainWindow* window = newMainWindow();
     window->createView(session);
+    // Since user is dragging and dropping, move dnd window to where
+    // the user has the cursor (correct multiple monitor setups).
+    window->move(QCursor::pos());
     window->show();
 }