Add mic grpc example

[apntt]

May I propose you to add this example in the repo, I think it would be easier to anyone to test vosk-server with gRPC directly with the microphone.

This example use Pyaudio to record microphone then use grpc send data to the server.

I know it's not much but if I can help you save some time. ;)

[nshmyrev]

Thank you! The idea is great, but I think you need to cleanup the code a bit. You do not need audio_file_name argument of gen function for example. The sample rate also better take from the microphone itself instead of enforcing the sample rate which some system doesn't support (44100 is more widely supported I think). Also, you can add capability to specify the device index and print the list of available devices so the user will be able to find the right device. Wrong device is a source of problems usually.

[apntt]

ok I'll do the modifications :)

[apntt]

I made some modifications and cleaning.
tell me if it's ok for you.

remark: PyAudio display some logs when initialised, not pretty but not blocking, do you want to not show those logs ? or it's ok for this example ?

[nshmyrev]

@vadimdddd please update this request so we can merge it now. Lets move to sounddevice instead of pyaudio