Better assign aria-* attributes to interactive block elements

[admturner]

Is your suggestion related to a problem? Please describe.

Blocks that serve as event triggers need ARIA attributes and there is no clear way to do that at the block or template level. When I add attributes directly the block in a template it triggers a block error in the editor. There are two ways around this that I've found:

1. Use the render_block filter to intercept specific blocks and filter the content using WP_HTML_Tag_Processor. This doesn't seem to work consistently for all blocks -- hidden elements appear to be ignored.
2. Use JS to add the attributes.

Describe alternatives you have considered.

The current methods work alright, but there should be a more reliable, consistent, and performant method.