Simplify the esmodule detection. If there's any import/exprt usage, it will return `Module` in ast.type otherwise `Script` when `isModule` is set to `"unknown"`
We need to handle cjs cases for client/server components when they're compiled to commonjs in some cases.
e.g. if there's an internal `_app.server.js` in nextjs, the assets in the dist files are compiled to cjs by swc. Or any 3rd party libraries are consumed could be cjs only.
### How it works
* Detect the source file is ESM or CJS first by detect if there's any ESM import/export
* Append the new exports or collect exports info based on the module type
