Improve Breadcrumbs by using Genesis breadcrumbs logic if available

[bobbingwide]

For themes which use the Genesis theme framework we can try to use the genesis breadcrumbs logic.

[bobbingwide]

I had a quick look at this. For the front-end the Genesis_Breadcrumb class has the logic we need. e.g.

if ( !$html ) {
		if ( class_exists( 'Genesis_Breadcrumb') ) {
			$gb = new Genesis_Breadcrumb();
			$html = $gb->get_output( [ 'labels' => [ 'prefix' => null] ]  );
		}
	}

BUT

• It doesn't work in the editor - similar problem to the WordPress SEO one? Improve Breadcrumbs block using WordPress SEO logic #2
• And apparently there's a problem with hierarchical CPTs. See https://github.com/studiopress/genesis/issues/1167 (if you have access). Not that I have any of those at present.

Temporary fix

I hacked build_crumbs() code to add an else statment that assumes we're dealing with page crumb.

} else {
   $crumbs[] = $this->get_page_crumb();
}

Pragmatic solution

Don't do anything with Genesis_Breadcrumbs at present.

[bobbingwide]

Ignoring the comment above since I no longer understand it. I'm closing this issue as there is support for Genesis breadcrumbs ( front end only), since v0.5.2.