Fix record and playback during install

Description

installers/naomi-setup.sh - Replace tabs with spaces

naomi/commandline.py - If default option is not available when selecting from a list, don't suggest a default

naomi/application.py - Don't load visualizations twice (caused duplicate visualizations). Set default vad from snr_vad to webrtc_vad. Fixed some formatting issues. Used "mic.play_file_sync" to play the beep showing that Naomi heard because the "mic.play_fp" started playing the captured voice data right afterward.

naomi/populate.py - Minor formatting issues

naomi/visualizations.py - clear current visualizations before loading, prevents duplicate visualizations.

plugins/audioengine/pyaudio-ae/pyaudioengine.py - noted problem with switching stream properties before previous stream has finished playing. Probably need to move to SoundDevice for audio.

plugins/stt/pocketsphinx-stt/g2p.py - cleaned up output

plugins/visualizations/terminal/terminal.py - Use system time when printing timestamp, not Naomi's timezone (which is part of the "clock" plugin).

python_requirements.txt - swap scikit-learn for sklearn.

Motivation and Context

This is a grab bag of fixes for things I ran into while preparing pull request 373 - New Pocketsphinx install procedure.

I think the first issue, "sklearn breaks installer" was fixed by PyPi. I've never seen an issue like that before and it was very annoying. It seemed like someone got over zealous about pushing the updated scikit-learn library. The other issues are minor and only really affected the ability to test your hardware setup by recording your voice and playing it back.

How Has This Been Tested?

I will test this on a raspberry pi 4 before merging it.

Screenshots (if appropriate):

Types of changes

[X] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

[X] My code follows the code style of this project.
[ ] My change requires a change to the documentation.
[ ] I have updated the documentation accordingly.
[ ] I have added tests to cover my changes.
[ ] All new and existing tests passed.

NaomiProject / Naomi