Allow us to change the CorsProxy used by CosmosAsync

[sophie]

📝 Provide a description of the new feature

In experimental settings or in spicetify's config, provide a option to change the cors proxy from the default https://cors-proxy.spicetify.app URL.

➕ Additional Information

This would allow us to bypass the issues with Genius in Lyrics Plus.

[em]

Our proxy works in the way that no cors proxy works (<cors-proxy>/<domain to be proxied>). Most of the proxies work in the way of <cors-proxy>/?<domain>. We would also need to add a way to configure the endpoint but it's not really the best idea because regardless if we would add it or not, the initial proxy will always be cors proxy. I don't think that's needed. If you want genius, I recommend editing the source code to use fetch and cors proxy of your choice. After disabling genius we did not have many people asking for it anyways