v1.8.0: Audio 代码重构与低功耗优化 (#943)

* Reconstruct Audio Code

* Remove old IoT implementation

* Add MQTT-UDP documentation

* OTA升级失败时，可以继续使用

main/audio/processors/audio_debugger.h

@@ -0,0 +1,22 @@
+#ifndef AUDIO_DEBUGGER_H
+#define AUDIO_DEBUGGER_H
+
+#include <vector>
+#include <cstdint>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+class AudioDebugger {
+public:
+    AudioDebugger();
+    ~AudioDebugger();
+
+    void Feed(const std::vector<int16_t>& data);
+
+private:
+    int udp_sockfd_ = -1;
+    struct sockaddr_in udp_server_addr_;
+};
+
+#endif