Keep old ally requests in place and add new ones on top

[cenullum]

When a new ally request arrives, it currently replaces the position of an older request. This often causes me to accidentally click on the new one instead of the old one, resulting in an unwanted alliance with the wrong player.

Instead, the older request should remain in its place, and the new request should be added on top of the list. This way, players can clearly distinguish between old and new ally requests without accidental misclicks.