CollectionDifference API implementation

[maximkrouk]

Checklist

• Reviewed the README and documents.
• Searched existing issues for ensure not duplicated.

Question

I want to mimic the behavior of CollectionDifference, so I started with

extension Array where Element: Differentiable {
    public func diff(from other: Array) -> StagedChangeset<Array> {
        StagedChangeset(source: self, target: other)
    }
}

And I'd like to implement Array.apply method, but I'm not sure what is the right way to apply StagedChangeset to an existing collection...

[maximkrouk]

Also I'm looking for how to implement Array.diff(from:by:) method