Migrating to modern c# namespace

Using the short namesapce declaration for conciseness

Models/BaseResult.cs

@@ -2,11 +2,10 @@ using System;
 
 using Newtonsoft.Json;
 
-namespace Icarus.Models
+namespace Icarus.Models;
+
+public class BaseResult
 {
-    public class BaseResult
-    {
-        [JsonProperty("message")]
-        public string Message { get; set; }
-    }
+    [JsonProperty("message")]
+    public string Message { get; set; }
 }