fix: Fixes spell mechanics and misc bugs (#1118)

- [X] Fixes NPE from account tags.
- [X] Fixes bad skill check due to missing cast to double.
- [X] Fixes water elemental duration.
- [X] Standardizes spell summon duration by expansion.

Projects/UOContent/Multis/Houses/HouseSign.cs

@@ -163,7 +163,7 @@ namespace Server.Multis
             if (m.AccessLevel < AccessLevel.GameMaster && Owner.Owner == null &&
                 Owner.DecayLevel != DecayLevel.DemolitionPending)
             {
-                var canClaim = Owner?.CoOwners.Count > 0 && Owner.IsCoOwner(m) || Owner.IsFriend(m);
+                var canClaim = Owner.IsCoOwner(m) || Owner.IsFriend(m);
 
                 if (canClaim && !BaseHouse.HasAccountHouse(m))
                 {

Projects/UOContent/Multis/Houses/PreviewHouse.cs

@@ -21,7 +21,7 @@ namespace Server.Multis
 
                 if (entry.Flags == 0)
                 {
-                    Item item = new Static((int)entry.ItemId);
+                    Item item = new Static(entry.ItemId);
 
                     item.MoveToWorld(new Point3D(X + entry.OffsetX, Y + entry.OffsetY, Z + entry.OffsetZ), Map);