Add an official utility to clone ref and reactive

[mrleblanc101]

I've stumbled upon this issue: vuejs/core#8975
The recommandation was to use toRaw to clone a ref or a reactive.

But since ref and reactive allow to compose reactive objects, toRaw still may not work for them due to how it works: https://stackoverflow.com/a/72633173/16716350

There are multiple cloning library, but shouldn't Vue ship their own utility for this ?
Since we already have multiple other utility to handle ref and reactive like https://vuejs.org/api/reactivity-utilities.html
It would be useful to add a toClone() or toCloned() utility.

I've also created an issue in vuejs/docs to document this:
vuejs/docs#3223

[mrleblanc101]

Since Vue 3 is modular, this would add any weigth.
We would have to decide if the utility only clone ref and reactive, or if it would also with with objects and deepObject