Support HTTP Proxy for AI Endpoints

Our PSU servers are located in an internal production network without internet access. It would be nice for the AI features if we could use our http proxy server to access the OpenAI compatible endpoint within our Azure environment. I've set the proxy under Settings/General/Plattform, the AI couldn't talk to Azure (and if this would be the right way: A NOPROXY option would be needed as many internal API services are not reachable by the proxy).