新增获取推流推流代理列表和ffmpeg源列表接口 (#3992)

src/Pusher/MediaPusher.h

@@ -33,11 +33,13 @@ public:
     void publish(const std::string &url) override;
     toolkit::EventPoller::Ptr getPoller();
     void setOnCreateSocket(toolkit::Socket::onCreateSocket cb);
-
+    std::shared_ptr<MediaSource> getSrc() { return _src.lock(); }
+    const std::string& getUrl() const { return _url; }
 private:
     std::weak_ptr<MediaSource> _src;
     toolkit::EventPoller::Ptr _poller;
     toolkit::Socket::onCreateSocket _on_create_socket;
+    std::string _url;
 };
 
 } /* namespace mediakit */