manage conflict (generic way) use toast to show error (#588)

* manage conflict (generic way) use toast to show error

* fix httpservice after merge conflict, adapt to use new repository

src/BlazorShared/Models/ErrorDetails.cs

@@ -0,0 +1,14 @@
+using System.Text.Json;
+
+namespace BlazorShared.Models
+{
+    public class ErrorDetails
+    {
+        public int StatusCode { get; set; }
+        public string Message { get; set; }
+        public override string ToString()
+        {
+            return JsonSerializer.Serialize(this);
+        }
+    }
+}