Dynamic routing with CEL interpolation and the forward-internal action

With the extension of CEL interpolation support to the url field on the forward-internal action, developers can now dynamically route requests to different internal endpoints based on request attributes such as URL, host, path, query string, and headers. This allows for flexible traffic management by leveraging variables during the request lifecycle. For instance, a rule can redirect traffic from `https://*.example.org` to `https://<subdomain>.internal`, where `<subdomain>` is extracted from the `req.host` variable using CEL interpolation. This capability enables dynamic routing in various scenarios, such as customer networks and developer machines, by utilizing custom headers or other attributes to route requests to specific internal endpoints. With this feature, developers can simplify complex workflows, manage traffic flows more effectively, and build scalable applications.