ListView CSS updates (#2517)
* initial ListView CSS updates
* add stories
* remove border radius from quiet ListItem
* remove border radiu from focus ring
* fix first and last items border radius
* fix double border on adjacent selected items
* fix to use emphasized styles by default
* fix border styling
* Update packages/@react-spectrum/list/src/listview.css
Co-authored-by: Daniel Lu <dlu@livefyre.com>
Co-authored-by: Danni <drobinson@livefyre.com>
Co-authored-by: Daniel Lu <dlu@livefyre.com>
