[runtime/gpu] Add GPU Hotwords

[zwglory]

Support hotword boosting for offline or streaming WeNet ASR models on GPUs.

For more information regarding the ctc_decoder, please refer to：Slyne/ctc_decoder#11

Here are our test results：

Tested ENV

• CPU：40 Core, Intel(R) Xeon(R) Silver 4210 CPU @ 2.20GHz
• GPU：NVIDIA GeForce RTX 2080 Ti

Hotwords file: https://huggingface.co/58AILab/wenet_u2pp_aishell1_with_hotwords/tree/main/models

AISHELL-1 Test dataset

• Test set contains 7176 utterances (5 hours) from 20 speakers.

model (FP16)	RTF	CER
offline model w/o hotwords	0.00437	4.6805
offline model w/ hotwords	0.00428	4.5841
streaming model w/o hotwords	0.01231	5.2777
streaming model w/ hotwords	0.01195	5.1850

AISHELL-1 hostwords sub-testsets

• Test set contains 235 utterances with 187 entities words.

model (FP16)	Latency (s)	CER	Recall	Precision	F1-score
offline model w/o hotwords	5.8673	13.85	0.27	0.99	0.43
offline model w/ hotwords	5.6601	11.96	0.47	0.97	0.63

Decoding result

Label	hotwords	pred w/o hotwords	pred w/ hotwords
以及拥有陈露的女单项目	陈露	以及拥有陈鹭的女单项目	以及拥有陈露的女单项目
庞清和佟健终于可以放心地考虑退役的事情了	庞清 佟健	庞青和董建终于可以放心地考虑退役的事情了	庞清和佟健终于可以放心地考虑退役的事情了
赵继宏老板电器做厨电已经三十多年了	赵继宏	赵继红老板电器做厨店已经三十多年了	赵继宏老板电器做厨电已经三十多年了

Refer to more results: https://huggingface.co/58AILab/wenet_u2pp_aishell1_with_hotwords/tree/main/results

Mainly developed by @FieldsMedal

[yuekaizhang]

Nice work. Would you mind merging the hotwords directory such that it would become a default settings?

1. merge model_repo_hotwords with regular model repos.
2. merge hotwords/readme.md into gpu/readme.md using a new section ### hotwords
3. hotwords.yaml could be under model_repo_x/scoring/, however, default hotwords_path is None like lm_path. In readme.md, set it to ./model_repo_x/scoring/hotwords.yaml to enable hotwords. e.g. sed -i /hotwords_path/xxx/ config_template.pbtxt
4. In this way, we may don't need convert_start_x.sh

[yuekaizhang]

Also, it would be nice if you could upload the script to comput f1 to scripts/.

[zwglory]

Also, it would be nice if you could upload the script to comput f1 to scripts/.

No problem, we are going to merge the hotwords directory and upload the f1 code.

[zwglory]

In the latest commit, we

1. remove the hotwords directory and merge it into regular model_repo_x;
2. add hotwords evaluation script;
3. update readme with hotwords usage and evaluation.

Please help us review this pr when you are free. Thanks♪(･ω･)ﾉ

[yuekaizhang]

Many thanks.