Refactor ReCClient for cleaner and more flexible design

- Removed unused `System.Xml.Linq` namespace import.
- Simplified code by removing `#if NETFRAMEWORK` directives.
- Added `ClientName` field to uniquely identify HTTP clients.
- Updated constructor to use named HTTP client with `ClientName`.
- Removed unused `_jsonOptions` field for better code clarity.

src/ReC.Client/ReCClient.cs

@@ -1,12 +1,9 @@
 using System.Text.Json;
-using System.Xml.Linq;
-
 #if NETFRAMEWORK
 using System;
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
-#else
 #endif
 
 namespace ReC.Client
@@ -14,11 +11,12 @@ namespace ReC.Client
     public class ReCClient
     {
         private readonly HttpClient _http;
-        private readonly JsonSerializerOptions _jsonOptions = new JsonSerializerOptions() { PropertyNameCaseInsensitive = true };
+
+        public static readonly string ClientName = Guid.NewGuid().ToString();
 
         public ReCClient(IHttpClientFactory httpClientFactory)
         {
-            _http = httpClientFactory.CreateClient();
+            _http = httpClientFactory.CreateClient(ClientName);
         }
 
         /// <summary>