[tts]add aishell3 hifigan egs

[tts]add vctk hifigan egs

[server] modify yaml

[audio] refactor audio arch

[audio]Add reference and doc string.

[audio][feature]Refactor and add doc string.

[server] add server test

fix gbk encode bug

[audio]refactor audio arch

[TTS]add rtf for synthesize, add more vocoder for synthesize.sh

[doc] VTuberTalk repo 

[server] update server cli

add examples

[TTS] fix Speedyspeech multi-speaker inference, test=tts