Add Visual Hint when Army is under Castle and Province attack

[Valek]

In the World view, i.e. not Battle view. If the army stands close to an enemy Castle, or Province, these structures will start firing arrows at your army. With all the multi-tasking involved in the game and the fact that the animation might not be noticeable given the scale of the units is easy to miss that your army is being attacked. I have lost whole armies to this.

Would it be possible to get some sort of notification. I understand that the regular notifications displayed in the left side might not be the best use case for this, as the army can intermittently get in the Castle range resulting in multiple notifications which could be annoying, but what about using some sort of visual hint in the Marshal's portrait at the Royal Court bar.