feat: 增加webrtc代理拉流 (#4389)

- 增加客户端模式，支持主动拉流、推流：
   - addStreamProxy接口新增支持whep主动拉流，拉流地址目前只兼容zlm的whep url。
   - addStreamPusherProxy接口新增支持whip主动推流，推流地址目前只兼容zlm的whip url。
   - 以上推流url格式为webrtc[s]://server_host:server_port/app/stream_id?key=value, 内部会自动转换为http[s]://server_host:server_port/index/api/[whip/whep]?app=app&stream=stream_id&key=value。

- 增加WebRtc p2p 模式：
  - 增加 ICE FULL模式。
  - 增加STUN/TURN 服务器。
  - 增加websocket 信令。
  - 增加P2P代理拉流。

---------

Co-authored-by: xia-chu <771730766@qq.com>
Co-authored-by: mtdxc <mtdxc@126.com>
Co-authored-by: cqm <cqm@97kid.com>

webrtc/WebRtcProxyPlayerImp.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT-like license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef ZLMEDIAKIT_WEBRTC_PROXY_PLAYER_IMP_H
+#define ZLMEDIAKIT_WEBRTC_PROXY_PLAYER_IMP_H
+
+#include "WebRtcProxyPlayer.h"
+
+namespace mediakit {
+
+class WebRtcProxyPlayerImp
+    : public PlayerImp<WebRtcProxyPlayer, PlayerBase>
+    , private TrackListener {
+public:
+    using Ptr = std::shared_ptr<WebRtcProxyPlayerImp>;
+    using Super = PlayerImp<WebRtcProxyPlayer, PlayerBase>;
+
+    WebRtcProxyPlayerImp(const toolkit::EventPoller::Ptr &poller) : Super(poller) {}
+    ~WebRtcProxyPlayerImp() override { DebugL; }
+
+private:
+
+    //// WebRtcProxyPlayer override////
+    void startConnect() override;
+
+    //// PlayerBase override////
+    void onResult(const toolkit::SockException &ex) override;
+    std::vector<Track::Ptr> getTracks(bool ready = true) const override;
+
+    //// TrackListener override////
+    bool addTrack(const Track::Ptr &track) override { return true; }
+    void addTrackCompleted() override;
+};
+
+} /* namespace mediakit */
+#endif /* ZLMEDIAKIT_WEBRTC_PROXY_PLAYER_IMP_H */