[EnhancedButton] support composable anchor tag

[mbrookes]

This would allow deprecation of linkButton and href props. EnhancedButton already supports <input>, but uses props to support anchor. This would also indirectly solve #1586.

(Arguably linkButton is already redundant - if href is set, then linkButton must be true.)

[mbrookes]

Seems this may already be possible (just not composable): #850 (comment). This is undocumented though.

[alitaheri]

@mbrookes Actually we should remove that. if people want to tun it into a link, then they can just wrap the component around <a>.

[mbrookes]

I thought that when I was updating the docs, and tried to change the example in order to replace href and linkButton, butt doesn't work as expected - only the text within <a></a> is clickable (and is the wrong colour without additional styling) - hence this PR. 😄

[alitaheri]

Oh... there's that -_- what about link? 😁 it takes a url and renders an <a> element. I understand the tenancy to use HTML attributes. an I think its better too, but href is used as a work around by some people, so i think we should deprecate it for the sake of better documentation of the expected behavior. we'll deprecate linkButton and href and document the expected caveat and behaviors of using link.

[mbrookes]

So, we deprecated linkButton and just detect the href prop. @alitaheri I didn't quite follow what you were saying about link vs. href, but I'm going to close this issue for now and we can revisit for the reworked Button.

[alitaheri]

Well since it would be a change in behavior. It would better have a new name. but since we're working on Button this is irrelevant now.