Positions the tab switcher in the top-center of the editor.

def set_dialog_position(self):
        """Positions the tab switcher in the top-center of the editor."""
        left = self.editor.geometry().width()/2 - self.width()/2
        top = self.editor.tabs.tabBar().geometry().height()

        self.move(self.editor.mapToGlobal(QPoint(left, top)))