Implement server.url

[Electroid]

What does this PR do?

This adds support for server.url from Bun.serve().

const server = Bun.serve({
  fetch() {
    return new Response();
  }
});

console.log(server.url instanceof URL); // true
console.log(server.url.protocol); // "http:"
console.log(server.url.hostname); // "localhost"
console.log(server.url.port); // 3000

For unix sockets, it also works.

const server = Bun.serve({
  unix: "/tmp/bun.sock",
  fetch() {
    return new Response();
  }
});

console.log(server.url instanceof URL); // true
console.log(server.url.protocol); // "unix:"
console.log(server.url.pathname); // "/tmp/bun.sock"

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

Closes #5758, #6064

[github-actions]

❌ @Electroid 5 files with test failures on bun-darwin-aarch64:

• test/bundler/esbuild/default.test.ts
• test/integration/next/default-pages-dir/test/dev-server.test.ts
• test/js/bun/test/test-test.test.ts
• test/js/bun/util/which.test.ts
• test/js/web/worker.test.ts

View test output

^{#e781c3e99f50721ee727b953393eebe500df339c}

[github-actions]

❌ @Electroid 7 files with test failures on bun-darwin-x64-baseline:

• test/js/bun/spawn/spawn-streaming-stdout.test.ts
• test/js/bun/util/which.test.ts
• test/js/node/fs/fs.test.ts
• test/js/node/watch/fs.watchFile.test.ts
• test/js/third_party/webpack/webpack.test.ts
• test/js/web/timers/setInterval.test.js
• test/js/web/timers/setTimeout.test.js

View test output

^{#e781c3e99f50721ee727b953393eebe500df339c}

[github-actions]

❌ @Electroid 6 files with test failures on bun-darwin-x64:

• test/js/bun/spawn/spawn-streaming-stdout.test.ts
• test/js/bun/util/which.test.ts
• test/js/node/fs/fs.test.ts
• test/js/node/watch/fs.watchFile.test.ts
• test/js/third_party/webpack/webpack.test.ts
• test/js/web/timers/setTimeout.test.js

View test output

^{#e781c3e99f50721ee727b953393eebe500df339c}

[Jarred-Sumner]

yay