Headline Block's auto anchor code is causing duplicate identical element ids

[acketon]

This code:

bu-blocks/src/blocks/headline/headline.js

Lines 88 to 94 in be9ee86

	// Generate an index-based value for the anchor attribute if it is not set.
	if ( ! anchor ) {
	const headlineBlocks = getBlocks().filter( e => e.name === 'editorial/headline' );
	const id = 'headline-' + ( headlineBlocks.length );
	setAttributes( { anchor: id } );
	}

should be removed as it causes duplicate element id's in a couple scenarios:

1. The code is only looking at headline blocks that are top level in the tree, it's not seeing headline blocks that are children of other blocks. When they are child blocks the id attribute is incorrect and leads to duplicates which SiteImprove then flags as an level A issue.

2. When duplicating an existing headline the anchor doesn't change so headline-1 becomes headline-1 on the duplicate block too. Admittedly this is how gutenberg works I think but is still not a great idea.

I'd suggest removing this feature as it isn't used anywhere and let the editor manually set the anchor in the anchor field.