draft of refactor to make custom confirm modal work for upload; need to further edit sb-file-uploader

Add support for custom confirm modal to sb-file-uploader

Show custom confirm modal when confirming project upload

got custom upload refactor of file upload working, and tested failure case

cleaned up debug code, make project file upload work

simplified logic around canceling file upload

removed old sb-file-uploader.jsx; fixed linter errors

reverted two components to use old strings, not shared

(can do that refactor another time)

removed unnecessary confirm container

removed stray comment

moved, updated sb file uploader tests, related project state tests

removed custom modal, to reduce scope of changes

sb file uploader test uses intl

This reverts commit 45cb96f2.

Also noticed that Delete aria label was not localized.

* split play-button into container and component
* revised sound library tile:
  * play button in upper right
  * smaller sound icon (make the tile less loaded)

Play button doesn’t have a ‘touch-outside’ listener to stop sounds. That seems to be ok as other events cause the sound to stop.

Both handleClick and handleMouseDown are needed. Must use handleMouseDown for `preventDefault` to skip setting focus on the item. handleClick is needed to prevent the Click from propagating to the item and selecting it.

Update UI play/stop button when the sound ends

Play button is larger (easier to touch). Can both start and stop sounds.
Sound doesn’t restart on mouseEnter if the sound is already playing.
Sound stops if you move off play button

Missing: stop button does not revert to play button when the sound finishes.

Add prop to library items to show a play button. If a play button is present the ‘play on hover’ only applies over the icon rather than the full tile.