decoder for open vocabulary keyword spotting (#505)

* various fixes to ContextGraph to support open vocabulary keywords decoder

* Add keyword spotter runtime

* Add binary

* First version works

* Minor fixes

* update text2token

* default values

* Add jni for kws

* add kws android project

* Minor fixes

* Remove unused interface

* Minor fixes

* Add workflow

* handle extra info in texts

* Minor fixes

* Add more comments

* Fix ci

* fix cpp style

* Add input box in android demo so that users can specify their keywords

* Fix cpp style

* Fix comments

* Minor fixes

* Minor fixes

* minor fixes

* Minor fixes

* Minor fixes

* Add CI

* Fix code style

* cpplint

* Fix comments

* Fix error

cmake/cmake_extension.py

@@ -151,6 +151,7 @@ class BuildExtension(build_ext):
         # Remember to also change setup.py
 
         binaries = ["sherpa-onnx"]
+        binaries += ["sherpa-onnx-keyword-spotter"]
         binaries += ["sherpa-onnx-offline"]
         binaries += ["sherpa-onnx-microphone"]
         binaries += ["sherpa-onnx-microphone-offline"]