feat: allow the server option to be Function

[alexander-akait]

• This is a bugfix
• This is a feature
• This is a code refactor
• This is a test update
• This is a docs update
• This is a metadata update

For Bugs and Features; did you add new tests?

will be later

Motivation / Use-Case

#5258
#4741

Breaking Changes

No

Additional Info

No

/cc @ckken

Configuration:

module.exports = {
    name: "app",
    devtool: false,
    target: "web",
    entry: "./src/index.js",
    mode: "development",
    devServer: {
      setupMiddlewares: (_, devServer) => [
        {
          name: "webpack-dev-middleware",
          middleware: require("webpack-dev-middleware").honoWrapper(devServer.compiler),
        },
        {
          name: "static",
          middleware: require('@hono/node-server/serve-static')({ root: './public' }),
        },
      ],
      app: () => new (require("hono").Hono)(),
      server: (_, app) => require("@hono/node-server").serve(app),
    },
  }

There are still some things need to solve, but locally works fine