Rework architecture

DiscordChatExporter.Domain/Internal/HttpClientExtensions.cs

@@ -0,0 +1,17 @@
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+namespace DiscordChatExporter.Domain.Internal
+{
+    internal static class HttpClientExtensions
+    {
+        public static async Task<JsonElement> ReadAsJsonAsync(this HttpContent content)
+        {
+            await using var stream = await content.ReadAsStreamAsync();
+            using var doc = await JsonDocument.ParseAsync(stream);
+
+            return doc.RootElement.Clone();
+        }
+    }
+}