aria-valid-attr-value mark missing aria-errormessage for review

Instead of failing the the aria-valid-attr-value rule, the following should be marked for review. This should happen in the aria-errormessage check.

<div role="textbox" aria-errormessage="my-error" aria-label="A textbox"></div>

Essentially, what needs to change is that we check for aria-errormessage if the target of the attribute exists in the DOM, and if it does not, return undefined to mark it for review, and add an incomplete message to the JSON file.

[straker]

Sounds good. Let me know if you need anything.

[patrickhulce]

Ah I see, so it’s not expected that aria-errormessage is only added when there is an error message then, it’s permanently there whether there is currently an error or not 👍

Thanks!