A whole new Quick Edit in Cloudflare Workers

Introduced a new Quick Edit experience for Cloudflare Workers within the dashboard, powered by VSCode for Web. This upgrade enables support for multiple JavaScript modules, provides a high-fidelity edge preview by using the same runtime as `wrangler dev`, displays helpful error messages with stack traces, and integrates JSDoc TypeScript syntax for typechecking and autocompletion. The implementation leverages MessageChannel for communication between the dashboard and the VSCode iframe, and has open-sourced key components of the VSCode extension and patches.