Move ErrorBoundary back into the app, fix IE error boundary

Update scratch-render to the latest version 

Make remaining text translatable, and prevent future regressions

Bitmap import and export

Add sprites, costumes, and backdrops from Ipzy

Revert localization of crash message.

We realized that the VM actually uses actual rotation center, so I moved the point where division by 2 happens into the VM

Change how information is sent to the vm to match the usual definitions the VM uses for that information

Fix errors when dragging in player mode

It doesn't work without an intl provider, which is mounted inside the error boundary.

Update libraries with new version of libgen

Update scratch-blocks to the latest version 

Upload a costume from camera

* Player mode

Add isPlayerOnly property on GUI. Move isFullScreen into mode reducer with isPlayerOnly.

Full screen needs to be a separate prop so that GUI knows what to show when exiting full-screen (either player-only or full editor).

- set `gui-body * {box-sizing: border-box;}` instead of expecting it to be set by the enclosing component/playground, and removed uses of content-box (adjusting sizes as needed) 
- Added `!isPlayerOnly` to the conditions for draggable sprites
- rewrote player example to use player mode.

Add translation to missing strings

Show "Backdrops" instead of "Costumes" in tab text if stage is selected.