Introducing Custom Domains for Workers

Introduces Custom Domains for Cloudflare Workers, allowing users to map a domain directly to a Worker. This feature leverages Cloudflare DNS to register the Worker as the origin, automatically handling DNS records and certificate issuance. It simplifies the developer experience by treating the custom domain as the origin server, enabling direct service calls via bindings and increasing the external request limit for Unbound usage to 1,000. It also allows Workers to invoke other Workers via standard HTTP requests.