Add HTTP(S) proxy (#208)

Source/GrasscutterTools/Eavesdrop/Event Args/ResponseInterceptedEventArgs.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Net;
+using System.Net.Http;
+using System.ComponentModel;
+using System.Threading.Tasks;
+
+using Eavesdrop.Network;
+
+namespace Eavesdrop
+{
+    public class ResponseInterceptedEventArgs : CancelEventArgs
+    {
+        private WebResponse _response;
+        public WebResponse Response
+        {
+            get => _response;
+            set
+            {
+                _response = value;
+                if (value is HttpWebResponse httpResponse)
+                {
+                    CookieContainer = new CookieContainer();
+                    CookieContainer.Add(httpResponse.Cookies);
+                }
+                else CookieContainer = null;
+            }
+        }
+
+        public WebRequest Request { get; }
+        public Uri Uri => Response?.ResponseUri;
+
+        public HttpContent Content { get; set; }
+        public CookieContainer CookieContainer { get; private set; }
+
+        public string ContentType
+        {
+            get => Response?.ContentType;
+            set
+            {
+                if (Response != null)
+                {
+                    Response.ContentType = value;
+                }
+            }
+        }
+        public WebHeaderCollection Headers
+        {
+            get => Response?.Headers;
+            set
+            {
+                if (Response == null) return;
+                foreach (string header in value.AllKeys)
+                {
+                    Response.Headers[header] = value[header];
+                }
+            }
+        }
+
+        public ResponseInterceptedEventArgs(WebRequest request, WebResponse response)
+        {
+            Request = request;
+            Response = response;
+        }
+    }
+}