Summary

This PR introduces a smart pointer called BindingCell.

When the "napi" feature is disabled, Root uses the sys_binding module as a simple alias for Box.

When the "napi" feature is enabled, Root uses the napi_binding module:

1. Root establishes a 1:1 relationship between a Rust instance and a JS Object.
2. Root creates a JS Object only when converting a Rust instance to a JS object.
3. The JS Object is hold a weak reference to the Rust instance. If the Rust instance is dropped,
   any attempt to access the JS Object will throw an exception indicating that the Rust instance has been dropped.
4. Root holds a napi_ref to the JS Object but does not manage its lifecycle. Instead, the JS Object is associated
   with another JS object (e.g., a Compilation JS object), ensuring it is not garbage-collected during that entity’s lifecycle.

By establishing a 1:1 relationship between the Rust instance and the JS Object, we can easily retain the JS Object associated with AssetInfo at creation, thereby preserving all user-added data on the JS Object, including any data keyed by Symbols.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).