proxy_request endpoint is accessible without authentication

[pgagnidze]

/api/proxy_request/ proxies arbitrary HTTP requests through the Jet Bridge server without authentication. ProxyRequestView extends BaseAPIView with no permission_classes set.

curl "https://your-jet-bridge/api/proxy_request/?url=https://checkip.amazonaws.com"
# Proxies the request from the server's IP, no token needed

Fix would be adding HasProjectPermissions to ProxyRequestView.