Implement drag and drop in React Aria (#1286)
* Initial commit for drag and drop
* Initial take on keyboard dnd
* Don't preventDefault in usePress if inside a draggable element
* Ignore drop targets inside an aria-hidden container
* Prevent normal keyboard events and pass dnd events through target
* Keep valid drop targets up to date and support drag activate event on keyboard
* Move focus to collection children
* Fix pointerType of pointer events outside storybook iframe in mobile safari
* Register focus visible global listeners on page load
* Somewhat working screen reader support
* Get collection drop targets working with screen readers
* Cancel press on drag start in Safari
* Prototype: allow tab key inside selectable items
* Add option to deselect items on press up
* Improve keyboard support for droppable collections and make examples prettier
* Some fixes for iOS voiceover
* iOS voiceover improvements
* Fix usePress
* Lint
* Setup @react-stately/dnd package
* Add draggable collection hooks
* Match native macOS behavior for dragging selection
* Support custom renderPreview function
* Remove getDropOperation prop from useDroppableItem
* Support for dropping on the collection root, and ARIA grid example
* Create useDescription hook to dedup description elements
* Centralize platform/browser checks in one place
* Don't fire onDropExit and onDropEnter when the new target is the same as the old one
* Implement auto scroll support in Safari on macOS
* Support no renderPreview option for useDraggableCollection
* Determine whether two drop targets are equivalent
* Add virtualized example
* Implement support for Home/End and PageUp/PageDown
* Support multiple items of the same type, and items with multiple representations
* Only render drop indicators when visible or not aria-hidden
* Add example of reordering a list
* Don't select on press start on drag handle
* Switch to grid hooks for examples
* Wait a frame to dispatch onDrop
* Internationalize messages
* Add initial tests for drag and drop
* Tests for useDroppableCollection
* useDraggableCollection tests
* Revert table test skips
* Add tests for usePress changes
* Add test for ariaHideOutside VO workaround
* Add tests for useListData changes
* Add missing return
Co-authored-by: Danni <drobinson@livefyre.com>
