Encode hotwords in C++ side (#828)

* Encode hotwords in C++ side

.github/scripts/test-python.sh

@@ -8,6 +8,8 @@ log() {
   echo -e "$(date '+%Y-%m-%d %H:%M:%S') (${fname}:${BASH_LINENO[0]}:${FUNCNAME[1]}) $*"
 }
 
+export GIT_CLONE_PROTECTION_ACTIVE=false
+
 log "test online NeMo CTC"
 
 url=https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-streaming-fast-conformer-ctc-en-80ms.tar.bz2