Wires WebCore::performLocalNetworkAccessCheck() (added in a prior patch) into NetworkResourceLoader at the two points where a load's resolved-connection address space becomes known: the final response and each redirect hop, since redirects don't flow through didReceiveResponse and could otherwise bypass the check entirely. Threads the requesting document's address space and secure-context status from WebProcess into NetworkProcess to support this. Adds a WebKitCocoa API test against the real Cocoa network stack and a layout test using the permission-stub testing hook. Part of the Local Network Access enforcement work (meta bug 250607).