Move mojom definitions of URL{Request,Response} into SDK

mojo/services/network/public/interfaces/http_connection.mojom

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module mojo;
 
+import "mojo/public/interfaces/network/network_error.mojom";
 import "network/public/interfaces/http_message.mojom";
-import "network/public/interfaces/network_error.mojom";
 import "network/public/interfaces/web_socket.mojom";
 
 interface HttpConnection {
   // Sets the OS send buffer size (in bytes) for the underlying socket.
   SetSendBufferSize(uint32 size) => (NetworkError result);
 
   // Sets the OS receive buffer size (in bytes) for the underlying socket.
   SetReceiveBufferSize(uint32 size) => (NetworkError result);
 };
 
@@ skipping 14 matching lines @@
   // following are not supported:
   // - negotiating subprotocol or extension;
   // - fragmented or non-text messages;
   // - failure or close notification;
   // - flow control.
   OnReceivedWebSocketRequest(HttpRequest request)
       => (WebSocket&? web_socket,
           handle<data_pipe_consumer>? send_stream,
           WebSocketClient? client);
 };