Framework: Support runtime adapters (Deno, Node.js, etc.)/serverless functions

[one-aalam]

Make Zarf adaptable to different JS runtimes (Node.js, Deno, Cloudflare, etc.)

• [x] Bun.js - Separate out the Bun.js server as an adapter
• [ ] Deno
• [ ] Node.js
• [ ] Cloudflare Workers

and support server-less functions providers like

• [ ] Netlify Functions
• [ ] Vercel Functions