yew-router's Link should give access to the NodeRef of the anchor element

[athanclark]

It's a simple concept - the <Link<T>> component from yew-router doesn't give full access to the internal <a> tag. I think adding a ref: NodeRef field to the LinkProps struct would be a good compromise.

Example use case: a search bar. Because <Link> uses <a> internally, and not <input type="submit">, we'd have to manually emit a click event to the <a> tag when a user presses the Enter key after typing-in their search. This could be done by coercing the NodeRef to a HtmlElement, and calling click().

There is a pending PR for this request - #2877