[New plugin] Music visualizers

[th-ch]

This PR implements a new plugin that replaces the video by a music visualizer:

• Butterchurn:
  
• Vudio:
  
• Wave:
  

New visualizers can be implemented by creating a new class with the same interface in the visualizers folder. Possible future improvements:

• Wave resizing seems to have issues, particularly in fullscreen
• have a toggle between the video and the visualizer (currently needs to disable the plugin)

[Zo-Bro-23]

Wow, that looks amazing! Can't wait to try it out.

have a toggle between the video and the visualizer (currently needs to disable the plugin)

Yes, that would be nice. Also, can we have an option to stop the visualizer when the app is not in focus? That will save GPU and CPU resources, and prevent the app from possibly lagging when brought back to focus. That's a usual issue with applications, but I'll have to test it out to see if it's present with this plugin.

[Araxeus]

I just stumbled upon a way to make youtube actually play only music ,(not even download the video)

Aka grab the request for video and replace it with audio only

So i was thinking about where to implement it in this app... Thought about adding it to the video-toggle plugin, and now thinking how it goes well with this one...

but maybe all of the above can be consolidated into one plugin?
(For example you could choose "visualizer" and "audio-only" when its a music video, and when its not do nothing)

Just throwing out ideas

Btw great job, it looks good 😎

[Zo-Bro-23]

I just stumbled upon a way to make youtube actually play only music ,(not even download the video)

That'll be great for saving resources and increasing performance.

but maybe all of the above can be consolidated into one plugin?

Yes, that might give a better user experience overall. Video toggle plugin with option to force no video, have visualizers instead, or have the original video available with the toggle.

[Araxeus]

Pretty sure you want migrations for this one

probably should use setDefaultPluginOptions

youtube-music/config/store.js

Line 13 in 35bd62c

setDefaultPluginOptions(store, "picture-in-picture");

[th-ch]

All these ideas above make sense (audio only, consolidating video toggle and visualizer, disable rendering when not focusing, etc) - I will merge the PR as is as a start, we can have follow up PRs for the rest!