Reorganize, shared entities from TypeScript SDK

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

Cloudflare.Tests/CloudflareClientTest.cs

@@ -1,10 +1,7 @@
-using System;
-using System.Collections.Generic;
 using System.Linq;
 using System.Net.Http;
 using System.Reflection;
 using AMWD.Net.Api.Cloudflare;
-using AMWD.Net.Api.Cloudflare.Auth;
 using Moq;
 using Moq.Protected;