Migrating to modern c# namespace

Using the short namesapce declaration for conciseness

Models/RegisterResult.cs

@@ -2,13 +2,12 @@ using System;
 
 using Newtonsoft.Json;
 
-namespace Icarus.Models
+namespace Icarus.Models;
+
+public class RegisterResult : BaseResult
 {
-    public class RegisterResult : BaseResult
-    {
-        [JsonProperty("username")]
-        public string Username { get; set; }
-        [JsonProperty("successfully_registered")]
-        public bool SuccessfullyRegistered { get; set; }
-    }
+    [JsonProperty("username")]
+    public string Username { get; set; }
+    [JsonProperty("successfully_registered")]
+    public bool SuccessfullyRegistered { get; set; }
 }