hide 'None' flag for flags in Land, RoadExtraObject

Author: LeftofZen

Gui/ViewModels/LocoTypes/Objects/LandViewModel.cs

@@ -1,5 +1,6 @@
 using Definitions.ObjectModels.Objects.Land;
 using Definitions.ObjectModels.Types;
+using PropertyModels.ComponentModel.DataAnnotations;
 
 namespace Gui.ViewModels;
 
@@ -24,6 +25,7 @@ public uint8_t NumImageAngles
 		set => Model.NumImageAngles = value;
 	}
 
+	[EnumProhibitValues<LandObjectFlags>(LandObjectFlags.None)]
 	public LandObjectFlags Flags
 	{
 		get => Model.Flags;

Gui/ViewModels/LocoTypes/Objects/RoadExtraViewModel.cs

@@ -1,11 +1,13 @@
 using Definitions.ObjectModels.Objects.Road;
 using Definitions.ObjectModels.Objects.RoadExtra;
+using PropertyModels.ComponentModel.DataAnnotations;
 
 namespace Gui.ViewModels;
 
 public class RoadExtraViewModel(RoadExtraObject model)
 	: LocoObjectViewModel<RoadExtraObject>(model)
 {
+	[EnumProhibitValues<RoadTraitFlags>(RoadTraitFlags.None)]
 	public RoadTraitFlags RoadPieces
 	{
 		get => Model.RoadPieces;