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/boards/echoear/EchoEar.cc

@@ -1,10 +1,9 @@
 #include "wifi_board.h"
-#include "audio_codecs/box_audio_codec.h"
+#include "codecs/box_audio_codec.h"
 #include "display/lcd_display.h"
 #include "application.h"
 #include "button.h"
 #include "config.h"
-#include "iot/thing_manager.h"
 #include "backlight.h"
 
 #include <wifi_station.h>