update docs of audio

clean code in paddlespeech/audio

format audio dir

update audio api in apps

[audio] merge develop into audio 

[s2t] update wenetspeech RESULT.md, add chunk=-1 result of online conformer

[draft]split paddle audio

* finetune add frozen

[audio] fix typo in kaldi.py

Removed useless spk_id in speech_server and streaming_tts_server from demos, and support bilingual server engine, test=tts (#2380)

* Removed useless spk_id in speech_server and streaming_tts_server from demos, and support bilingual server engine.

* fix ernie_sat, test=tts

* fix for comments, test=tts

Co-authored-by: yuehuayingxueluo <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>

[s2t] DataParallel init method changed, fixed conformer could not multi-gpu training and don't affect dy2st

[s2t] update wenetspeech streaming coformer result

* Revised must_neural_tone_words.