Common: Add HttpRequest to simplify HTTP requests

Too much boilerplate that is duplicated if we use curl directly.
Let's add a simple wrapper class that hides the implementation details
and just allows to simply make HTTP requests and get responses.

Source/Core/Common/HttpRequest.h

@@ -0,0 +1,32 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "Common/CommonTypes.h"
+
+namespace Common
+{
+class HttpRequest final
+{
+public:
+  HttpRequest();
+  ~HttpRequest();
+  bool IsValid() const;
+
+  using Response = std::optional<std::vector<u8>>;
+  Response Get(const std::string& url);
+  Response Post(const std::string& url, const std::vector<u8>& payload);
+  Response Post(const std::string& url, const std::string& payload);
+
+private:
+  class Impl;
+  std::unique_ptr<Impl> m_impl;
+};
+}  // namespace Common