Specifically in 2.0:
- Monitors cannot be dragged in fullscreen/player
- List monitors cannot be resized, have items added using the button or have their values edited.
- Slider monitors still work.

Including triple scrollbars on list monitors and fixing the say bubble fonts

Includes:
- context menu for switching to sliders, only on variables.
- width, height, min, max properties consumed from VM.

Fixes #1853

It was 435KB. Now it's 5KB. I used SVGOMG: https://jakearchibald.github.io/svgomg/

Root cause is probably the flex implementation on Safari.

Fixes #1955

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

* 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.