Allow a way to get images from image cache that supports a reverse proxy

[daredoes]

Currently, the art data URL is formed from the settings host and port values under http.

What I think would be ideal is some way to send the image data itself to the snapcast client so it can store a cached version itself on the client.

https://github.com/badaix/snapcast/blob/481f08199ca31c60c9a3475f1064e6b06a503d12/server/streamreader/pcm_stream.cpp#L489C88-L489C92

[badaix]

Don't know how your infrastructure looks like, but if the client is talking to the server via the proxy, doesn't it work to set the [http] host value to the IP of the proxy?

[daredoes]

So I'm using a reverse proxy, which means that I have to use a web address, not an IP address.

currently i have host set to 0.0.0.0 so it binds to the network.