[redesign] Improve the new tabs component so that it is accessible

[mansona]

The interaction for the tabs component has been added in #157 and this work needs to be improved so that it is fully accessible.

For guidance on how to make a tabs component accessible please refer to https://www.w3.org/TR/wai-aria-practices/examples/tabs/tabs-1/tabs.html

[mansona]

I'm closing this one for now because the corresponding component has been removed for now 👍