fix: Fixes various mobile packets and setting serials (#1618)

### Summary
- Removes old death packet that isn't used. Doubtful this causes issues with clients that are v4+.
- Removes duplicate incoming packets. Again, probably to fix some old client issues, doubtful it affects clients v4+.
- Fixes setting serials and entities in props/commands. Note: Disabled setting `Parent` since the new sector code has issues. We shouldn't rely on it anyway!
- Reverts a recent change to healthbars that should not have been made. Oops!

Projects/UOContent/Mobiles/BaseCreature.cs

@@ -3223,7 +3223,6 @@ namespace Server.Mobiles
 
                 ProcessDelta();
                 SendIncomingPacket();
-                SendIncomingPacket();
 
                 // TODO: This can be done in Parallel if there are lots of them.
                 var aggressors = Aggressors;
@@ -3841,7 +3840,6 @@ namespace Server.Mobiles
             OutgoingMobilePackets.CreateBondedStatus(buffer, Serial, false);
             Effects.SendPacket(Location, Map, buffer);
 
-            SendIncomingPacket();
             SendIncomingPacket();
 
             OnAfterResurrect();