Implement basic virtual Room support based on enet (#2803)

* Added support for network with ENet lib,

connecting is possible, but data can't be sent, yet.

* fixup! Added support for network with ENet lib,

* fixup! CLang

* fixup! Added support for network with ENet lib,

* fixup! Added support for network with ENet lib,

* fixup! Clang format

* More fixups!

* Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Clang again

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

src/network/room.h

@@ -0,0 +1,60 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+#include <memory>
+#include <string>
+#include "common/common_types.h"
+
+namespace Network {
+
+constexpr u16 DefaultRoomPort = 1234;
+constexpr size_t NumChannels = 1; // Number of channels used for the connection
+
+struct RoomInformation {
+    std::string name; ///< Name of the server
+    u32 member_slots; ///< Maximum number of members in this room
+};
+
+/// This is what a server [person creating a server] would use.
+class Room final {
+public:
+    enum class State : u8 {
+        Open,   ///< The room is open and ready to accept connections.
+        Closed, ///< The room is not opened and can not accept connections.
+    };
+
+    Room();
+    ~Room();
+
+    /**
+     * Gets the current state of the room.
+     */
+    State GetState() const;
+
+    /**
+     * Gets the room information of the room.
+     */
+    const RoomInformation& GetRoomInformation() const;
+
+    /**
+     * Creates the socket for this room. Will bind to default address if
+     * server is empty string.
+     */
+    void Create(const std::string& name, const std::string& server = "",
+                u16 server_port = DefaultRoomPort);
+
+    /**
+     * Destroys the socket
+     */
+    void Destroy();
+
+private:
+    class RoomImpl;
+    std::unique_ptr<RoomImpl> room_impl;
+};
+
+} // namespace Network