Feature/search replace api

[JamesG-Speechmatics]

Adds support in the client for a feature to search and replace words in the transcript on the server side.

Implementation is mostly borrowed from the existing code for specifying custom dictionary words, either via the command line or a specified file.

Testing

Base case with no replacements:

speechmatics rt transcribe --ssl-mode none --url ws://jamesg.dev-vms.speechmatics.io:9090 ~/sample.wav
So
welcome to
this
podcast
on
professor
J.R.R.
Tolkien.
And
I'd like
to

compared to

speechmatics rt transcribe --replacement-words podcast:doomsaying --ssl-mode none --url ws://jamesg.dev-vms.speechmatics.io:9090 ~/tolkien16_shortest.wav
So
welcome to
this
doomsaying
on
professor
J.R.R.
Tolkien.
And
I'd like
to

or with regexes and backcaptures

speechmatics rt transcribe --replacement-words '/(\w)\.(\w)\.(\w)\./:$1$2$3' --ssl-mode none --url ws://jamesg.dev-vms.speechmatics.io:9090 ~/tolkien16_shortest.wav
So
welcome to
this
podcast
on
professor
JRR
Tolkien.

With a file containing

[
{"from":"Tolkien", "to":"Smith"}
]

result is

speechmatics rt transcribe --replacement-words-file list.txt --ssl-mode none --url ws://jamesg.dev-vms.speechmatics.io:9090 ~/tolkien16_shortest.wav
So
welcome to
this
podcast
on
professor
J.R.R.
Smith.

error case

speechmatics rt transcribe --replacement-words '/(\w)\.(\w)\.(\w\./:$1$2$3' --ssl-mode none --url ws://jamesg.dev-vms.speechmatics.io:9090 ~/tolkien16_shortest.wav
TranscriptionError: Requested configuration is invalid: Invalid config: Invalid regex pattern: '(\w)\.(\w)\.(\w\.' - Parenthesis is not closed. [sessionid = a653fcc5-e937-402b-9d3f-fb573021f0bc]

[giorgosHadji]

LGTM