Table a11y fix

[xman343]

Changes

#1148 - Table failing due to subrow expand button failing button-name rule.

*Passing solution: Implemented aria-label for subrow expand button.

Testing

Testing will be conducted through the Cypress web a11y script. Any breaking changes will be evaluated through unit testing & visual tests.

I am also reading the examples with NVDA to assess their screen reader compatibility.

Docs

N/A

[xman343]

Switched from using label to aria-label because the former caused two unit tests (should render sub-rows and handle expansions and should render filtered sub-rows) to fail. Both solutions pass the Cypress a11y evaluation, and both are screen-reader legible. I'll keep this solution unless there is one that is supposed to be better.