SECURITY: Expand and improve SSRF Protections (#18815)

See https://github.com/discourse/discourse/security/advisories/GHSA-rcc5-28r3-23rr

Co-authored-by: OsamaSayegh <asooomaasoooma90@gmail.com>
Co-authored-by: Daniel Waterworth <me@danielwaterworth.com>

lib/final_destination/faraday_adapter.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+class FinalDestination
+  class FaradayAdapter < Faraday::Adapter::NetHttp
+    def net_http_connection(env)
+      proxy = env[:request][:proxy]
+      port = env[:url].port || (env[:url].scheme == "https" ? 443 : 80)
+      if proxy
+        FinalDestination::HTTP.new(
+          env[:url].hostname,
+          port,
+          proxy[:uri].hostname,
+          proxy[:uri].port,
+          proxy[:user],
+          proxy[:password],
+        )
+      else
+        FinalDestination::HTTP.new(env[:url].hostname, port, nil)
+      end
+    end
+  end
+end