message: add all ad types to test ads page
diff: <div>
  <app-ad size="leaderboard" pos="top" />
  + <app-ad size="leaderboard" pos="bottom" />
  <app-ad size="rectangle" pos="top" />
  + <app-ad size="rectangle" pos="bottom" />
  + <app-ad size="rectangle" pos="footer" />
  </div>
  