Reorganize, shared entities from TypeScript SDK

https://github.com/cloudflare/cloudflare-typescript/blob/v4.4.1/src/resources/shared.ts

Cloudflare/CloudflareClient.cs

@@ -1,6 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Globalization;
+using System.Globalization;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
@@ -10,7 +8,6 @@ using System.Security.Authentication;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using AMWD.Net.Api.Cloudflare.Auth;
 
 namespace AMWD.Net.Api.Cloudflare
 {