Support auto-refresh of the history panel

During the discussion of #1569, it was brought up that having an [auto-refresh (mode or always enabled) would prove useful](https://github.com/jazzband/django-debug-toolbar/pull/1569#issuecomment-1012917371). [@gone is attempting a PoC.](https://github.com/jazzband/django-debug-toolbar/pull/1569#issuecomment-1013198835)