Provide &Dependency to Lazy widget view fn

[nicksenger]

This is a small ergonomics improvement that I noticed would be beneficial when working with the Lazy widget. The change is just to call the provided view function with a reference to the specified Dependency.

This is useful when the data provided for Dependency originates from the widget tree state, and so we don't have a reference to it which lives for the required 'a lifetime bound on Dependency. In this case we need to take ownership of the data to use it for Dependency. Unfortunately, the provided view function must also satisfy the 'a bound, so the data needs to be cloned again if we want to move it into the view function for use there.

By providing view with a reference to the dependency stored in the lazy widget, we can defer this second clone until the cache is actually invalidated rather than doing it on every view. I think it also makes using Lazy a bit more intuitive.

I'd be happy to write an RFC if more explanation/examples are required to make this change

[hecrj]

I think it makes sense! Thanks 🙇