[Help wanted] And various language bindings for VAD

[csukuangfj]

#353 adds support for VAD.

However, it only adds the C++ API.

Help from the community is appreciated to support the following languages

• C
• Python
• Kotlin
• Go
• C#
• JavaScript
• Swift

We also need to add VAD + microphone examples

Note that all of the above can follow what we have done in sherpa-onnx

The major change is to replace onnx with ncnn. The remaining code
can be copied literally from sherpa-onnx.