[WIP] add CTC prefix beam search / hotwords / shallow fussion

[pkufool]

This PR implements the core part (c++/python/JNI) of CTC prefix beam search related decoding methods, including hotwords and rnnlm shallow fussion.

• [x] offline prefix beam search
• [x] offline hotwords
• [ ] offline rnnlm shallow fussion
• [ ] online prefix beam search
• [ ] online hotwords
• [ ] online rnnlm shallow fussion

BTW we release our recent progress on CTC models, see https://arxiv.org/pdf/2410.05101 for details.

[fuyanzhe]

请问这个request计划什么时候合并

[dohe0342]

Hello. I trained CR-CTC model and decoded streaming CTC model and got token repetition (ex. ref: 안녕하세요 / hyp: 안녕녕하세요)

So, I really need online prefix beam search.... Do you have any plans to release online ctc prefix beam search? Thank you!