feat(rule): Require unique aria labels in checkboxgroup & radiogroup

[WilcoFiers]

Update the group-labelledby check to enforce that in addition to having a shared label, radiobuttons and checkboxes with the same name also have a unique label. This impacts the checkboxgroup and radiogroup rules.

I merged in a fix from #1314, which changes the gruntfile. We should probably more that PR first.

Closes #1111

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• Follows the commit message policy, appropriate for next version
• Has documentation updated, a DU ticket, or requires no documentation change
• Includes new tests, or was unnecessary
• Code is reviewed for security by: @dylanb

[dylanb]

Why not always fail this even when there is no shared label?

[dylanb]

@WilcoFiers seems like the change to make @stephenmathieson a code owner broke our ability to approve changes in that code

[jeeyyy]

@dylanb PR - #1331, fixed the codeowners issue.

[naltatis]

Feedback: Just updated axe an ran into this check. We finally could find the issue, we were having, but had to read through the tests and code modifications here to understand what was wrong.

This is the message we recieved

Ensures related <input type="radio"> elements have a group and that the group designation is consistent https://dequeuniversity.com/rules/axe/3.2/radiogroup?application=axeAPI

Fix any of the following:
  Elements with the name "segments-deliveryaddress-deliveryButtons" do not all have a unique label, referenced through aria-labelledby
  Element does not have a containing fieldset or ARIA group
  #billing-radiobutton

The actual problem was, that our radio buttons had a aria-labelledby that was pointing to the groups legend. Additionally the radios had an individual label (connected via for/id and label > input nesting), which we thought was sufficient. We were able to get rid of the error by expanding the aria annotiation by the radio inputs label-id aria-labelledby="legend-id" -> aria-labelledby="legend-id label1-id".
The error message above and the linked documentation did not point to that.

Maybe you should consider improving the message.

[dylanb]

@naltatis Do you think you could create a new issue in this project that references this and also maybe suggest a text that might have helped you figure out what was going on?