DeliveryAdminWindow: Small quality of life fixes

Elwig/Helpers/Weighing/InvalidScale.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Elwig.Helpers.Weighing {
+    public class InvalidScale : IScale {
+
+        public string Manufacturer => "NONE";
+        public string Model => "NONE";
+        public string ScaleId { get; private set; }
+        public int InternalScaleNr => 0;
+        public bool IsReady => false;
+        public bool HasFillingClearance => false;
+        public int? WeightLimit => null;
+        public string? LogPath => null;
+
+        public InvalidScale(string id) {
+            ScaleId = id;
+        }
+
+        public void Dispose() {
+            GC.SuppressFinalize(this);
+        }
+
+        public Task<WeighingResult> Weigh() {
+            throw new NotImplementedException();
+        }
+
+        public Task<WeighingResult> GetCurrentWeight() {
+            throw new NotImplementedException();
+        }
+
+        public Task Empty() {
+            throw new NotImplementedException();
+        }
+
+        public Task GrantFillingClearance() {
+            throw new NotImplementedException();
+        }
+
+        public Task RevokeFillingClearance() {
+            throw new NotImplementedException();
+        }
+    }
+}