Add commands for muting and toggling of audio sources.

[Snowdrama]

Main Changes:

• Added 2 new commands "SetAudioMute" and "ToggleAudioMute"
• Moved some of the OBS-websocket feature code into their own modules.
• Removed the "Ok" println! when a websocket response doesn't have an error as it clutters output when you start doing single inputs with multiple commands

[Snowdrama]

Closing so the #8 can go through first since this will need to be tweaked after that goes in. I'll do a new PR once I've updated it.