Accessibility/tables

[snide]

Summary

Fixes #1028
Possibly fixes #749

This adds some aria labeling to the search bar and table. Due to some funkiness with aria-live in various browsers at the moment some of it doesn't work (specifically re-reading the content after its been updated). However, this is how the aria-live spec says to do stuff.

Methods used

Searchbar now has an aria label that announces what it does and lets the user know if the content will auto update or not.

BasicTable now includes a caption which announces the amount of items present through aria-live. In combo with search bar this should read as the content changes. However, right now that isn't the case due to the bugs mentioned above. Worst case scenario is that there is a hidden table caption that does nothing at the moment.

https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Live_Regions

Checklist

• This was checked in mobile
• This was checked in IE11
• This was checked in dark mode
• Any props added have proper autodocs
• Documentation examples were added
• A changelog entry exists and is marked appropriately
• This was checked for breaking changes and labeled appropriately
• Jest tests were updated or added to match the most common scenarios
• This was checked against keyboard-only and screenreader scenarios

[chandlerprall]

LGTM, code review and aria-live investigations