Toast remove and timeout (#224)
* adding remove to state and setting it via aria
* toast delete working with a key
* adding toast remove timer
* getting toast placement from provider
* fixing tests to support onRemove
* updating storybook to demostrate toast timeouts
* toast code cleanup
* adding onRemove tests
* timer is paused on hover or focus
* cleaning up timer.js for toast
* renaming the timer file
* seperating toast state and props
Co-authored-by: Daniel Lu <dlu@livefyre.com>
Co-authored-by: Danni <darobins@adobe.com>
