Smart Tab Mute + door Tonton Jo

Imagine you have a tab open in the background playing music. Now, in your current tab, you start playing a video. Smart Tab Mute will automatically mute the background tab and unmute it again once the video has finished playing.

Functions:
- Allow only one tab to play sound at a time
- Whitelist: Prevent a tab from being muted using a domain and prevent other tabs from making noise.
- Ignorelist: Will not mute other tabs when playing sound (useful for notifications)
- Unmute tab when selected/focused

This add-on is based on the "Smart Tab Mute" Chrome extension by @neuling2k and "Smart Tab Mute" by @noniq.

I fixed the plugin, as the original one was failing to unmute the previously audio-playing tab and enhanced it to fit my needs.

Special thanks to @Gregoux06, who helped me a lot in fixing this plugin.