a11y - Remove unnecessary aria-describedbys

[rebeccaalpert]

A majority of buttons look to have both an aria-describedby and aria-label, where the aria-describedby is unnecessary/adding noise/pointing to a tooltip that contains the same content as the aria-label. Instead the aria-describedby should be removed from these buttons (the content being pointed to isn't really "describing" the button as much as it is labeling it) and either update the aria-label to match the tooltip content or use aria-labelledby instead