Request window attention when round starts/restarts.

Content.Server/Players/PlayerSessionExt.cs

@@ -0,0 +1,14 @@
+using Content.Shared.Network.NetMessages;
+using Robust.Server.Interfaces.Player;
+
+namespace Content.Server.Players
+{
+    public static class PlayerSessionExt
+    {
+        public static void RequestWindowAttention(this IPlayerSession session)
+        {
+            var msg = session.ConnectedClient.CreateNetMessage<MsgRequestWindowAttention>();
+            session.ConnectedClient.SendMessage(msg);
+        }
+    }
+}