add internal node modules to import map (deno)

[mavdotjs]

When adding a library via deno task esm:add ..., the CLI should automatically add an import map for any internal node modules imported by ...

{
  "imports": {
    "lib": "https://esm.sh/v131/*lib@4.2.0",
    "lib2": "https://esm.sh/v131/*lib2@0.1.69",
  },
  "scopes": {
    "https://esm.sh/v131/": {
      "events": "node:events" // < if 'events' is imported by lib or lib2, this would be added here
    }
  }
}