Add threads to the transcription process

[loganwyas]

There are currently threads that keeps the UI from crashing while the transcription is being done. However, these could be utilized to speed up the transcription.

What is required for this issue to be completed:

• Find a Python library that does threading well (whether that is what we are currently using, or something else)
• Reconfigure the functions in diarizationAndTranscription.py to use threads to improve the performance of the application
• If possible, report the difference in speed based on audio length