Detect the EndOfUtterance event and print it

[JamesG-Speechmatics]

Adds the --end-of-utterance-silence-trigger flag to the CLI, to control the parameter for detecting end of utterances (periods of silence)

"transcription_config": {
    "conversation_config": { 
        "end_of_utterance_silence_trigger": 1.8
    }
}

For json output mode, the EndOfUtterance message will be printed. For text output mode, the text [EndOfUtterance] will be printed.

$ speechmatics transcribe --end-of-utterance-silence-trigger 1.8 --enable-partials --ssl-mode none --url ws://localhost:9000/ ~/long_silences.wav
This
is
an
audio
file
with
some
quite.
[EndOfUtterance]
Long
silences.
[EndOfUtterance]

[giorgosHadji]

LGTM, can we add the usual cli test as well please?

[giorgosHadji]

current master is on 3.0.5 already btw