https://linear.app/unleash/issue/2-758/add-variant-improve-the-flow
### Variants form
- Fix variants edit form to follow natural tab order;
- Update variants form UI to new design with multiple improvements and
fixes, including a sticky header;
- New variants are now added at the bottom of the edit form instead of
at the top, with a smooth scroll and focus;
### Change requests
- On the variants diff, use variant names instead of index;
- Use an object-based diff logic (instead of array-based) for cleaner
diffs on variants (thanks @thomasheartman !);
- Display a table with the new variants data and display the diff on a
`TooltipLink`;
- Adapt strategy CR changes to the new `TooltipLink` logic for
consistency;
### Other
- `TooltipLink` and `Badge` components are now tab-selectable;
- Small enhancements, refactors and improvements;
---------
Co-authored-by: Gastón Fournier <gaston@getunleash.io>
Fixes an issue where the `HtmlTooltip` arrow would no longer work after
a regression included with https://github.com/Unleash/unleash/pull/2891
Also adds the arrow prop to most usages of the tooltip to keep
consistency.
