feat: Copy static properties from fs onto ufs

[phated]

Thank you for this awesome library! 🙏

I've been using it to fuse memfs and node's fs for use with the wasmer-js project (before they rewrote it in rust) and found that a few properties were missing on the final fs object.

This assigns the values when you use an fs (so the latest is copied).

[phated]

An alternative implementation I considered was using getters and a loop lookup from each fss, but then you can't accurately detect a missing property and the getters would have to throw if the no fss provided the property.

[G-Rath]

@phated would you mind rebasing so that the new CI changes are picked up?

[phated]

@G-Rath I used the "sync fork" button in the github UI but it seems to have merged correctly. Let me know if that works.